{"id":"CVE-2026-91983","revision":null,"records":[{"revision":"bb50a519133e425eab455dbfd7cba8fb","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-91983","aliases":[],"title":"Vikunja before 2.6.0 API Token Scope Bypass via expand Parameter","description":"Vikunja before 2.6.0 contains an API token scope bypass vulnerability in task read endpoints where authorization fails to inspect query string parameters. Attackers with limited token scopes can use the expand parameter to access restricted data like comments, reactions, and time entries without proper permission verification.","state":0,"publishedAt":"2026-09-15T15:18:26.899+00:00","modifiedAt":"2026-09-15T15:52:07.941+00:00","affected":[{"ecosystem":"Vendor product","name":"vikunja","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"go-vikunja\",\n                    \"product\": \"vikunja\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:golang/code.vikunja.io/api\",\n                    \"versions\": [\n                        {\n                            \"version\": \"1.0.0\",\n                            \"lessThan\": \"2.6.0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"2.6.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","score":5.3,"severity":"MEDIUM"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","score":4.3,"severity":"MEDIUM"}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9rg3-v78m-26q8","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-api-token-scope-bypass-via-expand-parameter"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-91983","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-91983","identifiers":["CVE-2026-91983"]},"retained":false,"historicalAffected":[]},{"revision":"6fd54de68a8d4b7481342ac229eb0510","observedAt":"2026-11-07T15:25:10.652+00:00","statement":{"source":"euvd","id":"EUVD-2026-78654","aliases":["CVE-2026-91983","GHSA-phph-c358-5mwm","GHSA-9rg3-v78m-26q8"],"title":"Vikunja before 2.6.0 contains an API token scope bypass vulnerability in task read endpoints where authorization fails to inspect query string parameters. Attackers with limited token scopes can use the expand parameter to access restricted…","description":"Vikunja before 2.6.0 contains an API token scope bypass vulnerability in task read endpoints where authorization fails to inspect query string parameters. Attackers with limited token scopes can use the expand parameter to access restricted data like comments, reactions, and time entries without proper permission verification.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","score":5.3,"severity":null}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9rg3-v78m-26q8","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-api-token-scope-bypass-via-expand-parameter"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-78654","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Sep 15, 2026, 3:18:26 PM","dateUpdated":"Sep 15, 2026, 3:52:07 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-78654","identifiers":["EUVD-2026-78654","CVE-2026-91983","GHSA-phph-c358-5mwm","GHSA-9rg3-v78m-26q8"]},"retained":false,"historicalAffected":[]},{"revision":"493d7e010aa2450cb7bbd1f274ff19ec","observedAt":"2026-10-25T16:19:22.228+00:00","statement":{"source":"nvd","id":"CVE-2026-91983","aliases":[],"title":"Vikunja before 2.6.0 contains an API token scope bypass vulnerability in task read endpoints where authorization fails to inspect query string parameters. Attackers with limited token scopes can use the expand parameter to access restricted…","description":"Vikunja before 2.6.0 contains an API token scope bypass vulnerability in task read endpoints where authorization fails to inspect query string parameters. Attackers with limited token scopes can use the expand parameter to access restricted data like comments, reactions, and time entries without proper permission verification.","state":0,"publishedAt":"2026-09-15T16:17:55.373+00:00","modifiedAt":"2026-09-16T20:16:09.343+00:00","affected":[],"metrics":[{"system":"CVSS 4.0 · disclosure@vulncheck.com · Secondary","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","score":5.3,"severity":"MEDIUM"},{"system":"CVSS 3.1 · disclosure@vulncheck.com · Primary","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","score":4.3,"severity":"MEDIUM"}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9rg3-v78m-26q8","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-api-token-scope-bypass-via-expand-parameter"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91983","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Deferred","weaknesses":["CWE-863"],"productCriteria":[],"sourceDates":{"published":"2026-09-15T16:17:55.373","lastModified":"2026-09-16T20:16:09.343"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-91983","identifiers":["CVE-2026-91983"]},"retained":false,"historicalAffected":[]},{"revision":"0302d3b294d1417ea58308ca7722810f","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-9rg3-v78m-26q8","aliases":["CVE-2026-91983","GO-2026-6726"],"title":"Vikunja: API token scopes bypassed via task expand parameter (comments, reactions, time entry counts)","description":"## Summary\n\nAPI token permission checks only match the HTTP method and route path. The `expand` query parameter on task read endpoints embeds data from other permission groups (task comments, reactions, time entry counts) without checking whether the token holds those scopes. A token scoped only to `tasks` read permissions can therefore read task comments and reactions it was explicitly not granted.\n\n## Details\n\n`models.CanDoAPIRoute` (`pkg/models/api_routes.go`, ~line 440) authorises API tokens purely by comparing `method` and `c.Path()` against the routes stored for each granted permission group. The query string is never consulted.\n\nThe task read endpoints accept `expand`:\n\n- `GET /api/v1/tasks/:task`, `GET /api/v1/tasks` (`pkg/models/tasks.go` ReadOne/ReadAll, `pkg/models/task_collection.go`)\n- `GET /api/v2/tasks/:id`, `GET /api/v2/tasks`, `GET /api/v2/projects/:project/tasks` (`pkg/routes/api/v2/tasks.go`, `task_collection.go`)\n\nAccepted values include `comments`, `comment_count`, `reactions`, `time_entries_count`. `addMoreInfoToTasks` (`pkg/models/tasks.go`, ~line 683) loads and embeds that data. At that layer only a `web.Auth` (the plain owner user, resolved by `auth.GetAuthFromClaims`) is available, so the token's scopes cannot be enforced there either.\n\nResult: the `tasks_comments`, `reactions`, and `time_entries` permission groups are advisory for any data reachable through a task expansion.\n\n## Impact\n\nA holder of an API token scoped to `tasks: [read_one]` or `tasks: [read_all]` (or `projects_views_tasks: [read_all]`) can read the full bodies of task comments, all reactions, and time entry counts on every task the token owner can access, despite `GET /api/v1|v2/tasks/:task/comments` and the reactions endpoints correctly returning 401 for the same token.\n\nThe leak is limited to data the token owner can already see, and is read-only. The realistic victim is a user who grants a narrowly scoped token to a third-party integration expecting comments to stay private.\n\n## Proof of Concept\n\nAgainst the test fixtures (`pkg/db/fixtures/api_tokens.yml`, token 1 has `{\"tasks\":[\"read_all\",\"update\"]}`, plaintext `tk_2eef46f40ebab3304919ab2e7e39993f75f29d2e`):\n\n```\nGET /api/v2/tasks/1/comments\nAuthorization: Bearer tk_2eef46f40ebab3304919ab2e7e39993f75f29d2e\n-> 401 {\"code\":11,\"message\":\"missing, malformed, expired or otherwise invalid token provided\"}\n\nGET /api/v2/tasks?expand=comments&filter=id%3D1\nAuthorization: Bearer tk_2eef46f40ebab3304919ab2e7e39993f75f29d2e\n-> 200, response items[0].comments contains the full comment objects\n```\n\nSame behaviour with `expand=reactions`, and on the v1 endpoints `GET /api/v1/tasks?expand=comments` / `GET /api/v1/tasks/1?expand=comments`. Any user-created token with only `tasks` read permissions reproduces this.\n\n## Recommended Fix\n\nEnforce expansions in the single existing choke point, `models.CanDoAPIRoute`: after the method/path match succeeds, read `c.QueryParams()[\"expand\"]` and require the token to hold the owning group's read permission for each value, e.g.\n\n- `comments`, `comment_count` -> `tasks_comments.read_all`\n- `reactions` -> `reactions.read_all`\n- `time_entries_count` -> `time_entries.read_all`\n\n(`subtasks`, `buckets`, `is_unread` are task-level data and need nothing extra.) Doing this in the middleware covers both v1 and v2 without handler or model changes. Add a table-driven test alongside `pkg/webtests/api_token_method_matching_test.go` asserting a `tasks`-only token gets 401 with `expand=comments` and 200 once `tasks_comments.read_all` is added.","state":0,"publishedAt":"2026-10-09T20:51:52+00:00","modifiedAt":"2026-10-19T21:41:16.6222921+00:00","affected":[{"ecosystem":"Go","name":"code.vikunja.io/api","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"1.0.0"},{"kind":"fixed","version":"2.6.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V4","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9rg3-v78m-26q8","https://nvd.nist.gov/vuln/detail/CVE-2026-91983","https://github.com/go-vikunja/vikunja/pull/3688","https://github.com/go-vikunja/vikunja/commit/077dc4de79ce6f1ab59215a2c7bf9b30423685f2","https://github.com/go-vikunja/vikunja","https://github.com/go-vikunja/vikunja/releases/tag/v2.6.0","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-api-token-scope-bypass-via-expand-parameter"],"sourceUrl":"https://github.com/advisories/GHSA-9rg3-v78m-26q8","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-9rg3-v78m-26q8","identifiers":["GHSA-9rg3-v78m-26q8","CVE-2026-91983","GO-2026-6726"]},"retained":false,"historicalAffected":[]},{"revision":"ed5a419867d840869e967a7b7a74582f","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-phph-c358-5mwm","aliases":[],"title":"Duplicate Advisory: Vikunja: API token scopes bypassed via task expand parameter (comments, reactions, time entry counts)","description":"### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-9rg3-v78m-26q8. This link is maintained to preserve external references.\n\n### Original Description\nVikunja before 2.6.0 contains an API token scope bypass vulnerability in task read endpoints where authorization fails to inspect query string parameters. Attackers with limited token scopes can use the expand parameter to access restricted data like comments, reactions, and time entries without proper permission verification.","state":2,"publishedAt":"2026-09-15T18:32:30+00:00","modifiedAt":"2026-10-09T21:00:07.1311089+00:00","affected":[{"ecosystem":"Go","name":"code.vikunja.io/api","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"1.0.0"},{"kind":"last_affected","version":"2.5.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","score":null,"severity":null},{"system":"CVSS_V4","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9rg3-v78m-26q8","https://nvd.nist.gov/vuln/detail/CVE-2026-91983","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-api-token-scope-bypass-via-expand-parameter"],"sourceUrl":"https://github.com/advisories/GHSA-phph-c358-5mwm","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-phph-c358-5mwm","identifiers":["GHSA-phph-c358-5mwm"]},"retained":false,"historicalAffected":[]},{"revision":"2cc6b8fe21f048cda17517e3cd754db8","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GO-2026-6726","aliases":["CVE-2026-91983","GHSA-9rg3-v78m-26q8"],"title":"Vikunja: API token scopes bypassed via task expand parameter (comments, reactions, time entry counts) in code.vikunja.io/api","description":"Vikunja: API token scopes bypassed via task expand parameter (comments, reactions, time entry counts) in code.vikunja.io/api.\n\nNOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions.\n\n(If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.)\n\nThe additional affected modules and versions are: code.vikunja.io/api from v1.0.0 before v2.6.0.","state":0,"publishedAt":"2026-10-19T21:08:26+00:00","modifiedAt":"2026-10-19T21:31:52.830337+00:00","affected":[{"ecosystem":"Go","name":"code.vikunja.io/api","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9rg3-v78m-26q8","https://nvd.nist.gov/vuln/detail/CVE-2026-91983","https://github.com/go-vikunja/vikunja/commit/077dc4de79ce6f1ab59215a2c7bf9b30423685f2","https://github.com/go-vikunja/vikunja/pull/3688","https://github.com/go-vikunja/vikunja/releases/tag/v2.6.0","https://www.vulncheck.com/advisories/vikunja-before-2.6.0-api-token-scope-bypass-via-expand-parameter"],"sourceUrl":"https://osv.dev/vulnerability/GO-2026-6726","license":"OSV · upstream source license applies","key":"osv:GO-2026-6726","identifiers":["GO-2026-6726","CVE-2026-91983","GHSA-9rg3-v78m-26q8"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-08T14:04:21.6524616+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-08T14:04:21.6524616+00:00","lastSuccessAt":"2026-11-08T14:04:21.8442875+00:00","error":null,"lastVerifiedAt":"2026-11-08T14:04:21.8442884+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-eaa64dac63caa79c8d4905619258c41c51b39e461b996124e1a21b5e85e7e738-4b0775bb0fc73c3ceeed66f8f17640894d61d654f97ee9386046b283ad9f9876","complete":true,"records":421100,"lastAttemptAt":"2026-11-08T14:04:21.1432513+00:00","lastSuccessAt":"2026-11-08T14:04:21.1228768+00:00","error":null,"lastVerifiedAt":"2026-11-08T14:04:21.1432513+00:00","snapshotPublishedAt":"2026-11-08T13:27:32+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-383c643166b94ac4b6a615647191978e","complete":true,"records":13654,"lastAttemptAt":"2026-11-08T14:04:47.6384375+00:00","lastSuccessAt":"2026-11-08T13:04:50.073+00:00","error":null,"lastVerifiedAt":"2026-11-08T13:04:50.073+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-08T14:04:21.6524616+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-08T14:04:21.6524616+00:00","lastSuccessAt":"2026-11-08T14:04:21.8452187+00:00","error":null,"lastVerifiedAt":"2026-11-08T14:04:21.8452194+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-ceefbd28b79c4b75ac56c9c678246411","complete":false,"records":13666,"lastAttemptAt":"2026-11-08T14:04:46.9956646+00:00","lastSuccessAt":"2026-11-08T14:04:46.992+00:00","error":null,"lastVerifiedAt":"2026-11-08T14:04:46.992+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13185,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-08T14:04:21.5047325+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-08T14:04:21.5047325+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-08T14:04:21.2941446+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-08T14:04:21.2941446+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-964c14035e6f0f6478b2870fad6a7ef9f6045876d4a12af2c2e514521e54b6af","complete":true,"records":3055,"lastAttemptAt":"2026-11-08T14:04:21.6167179+00:00","lastSuccessAt":"2026-11-08T11:07:12.1927025+00:00","error":null,"lastVerifiedAt":"2026-11-08T14:04:21.6167179+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-f8647d7ba64b1ba0dfdc7130944766d5b36d5b77d18fff0c79e651a4cff3c2b9","complete":true,"records":231293,"lastAttemptAt":"2026-11-08T14:04:21.3943214+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-08T14:04:21.3943214+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}