{"id":"CVE-2026-88877","revision":null,"records":[{"revision":"5d0a23f6e0cf479bac4b950fa54585d8","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-88877","aliases":[],"title":"Traefik v3.7.0 Authentication Bypass via from-to-www-redirect","description":"Traefik is a HTTP reverse proxy and load balancer. In versions >= v3.7.0 and <= v3.7.11, the Kubernetes ingress-nginx provider mishandles Ingresses that carry both an authentication annotation and the nginx.ingress.kubernetes.io/from-to-www-redirect annotation. For such Ingresses the provider creates an additional 'sibling' router that matches on the host alone, carries only the RedirectRegex middleware, and still points at the parent router's protected backend service. Because RedirectRegex is not a terminal handler, a request its pattern does not match is forwarded to the backend, and because the redirect pattern only accepts a numeric port while Traefik's host matcher canonicalizes the authority via net.SplitHostPort, a request with a non-numeric or empty port (for example 'Host: www.example.com:x') selects the sibling router, misses the redirect, and is proxied to the protected backend with none of the Ingress's annotation-derived middlewares applied. This discards not only authentication (e.g. BasicAuth) but every annotation-derived middleware, including source-IP allowlisting. Traefik v2 and v3 releases before v3.7.0 are not affected. The issue is fixed in v3.7.12.","state":0,"publishedAt":"2026-09-10T13:05:29.471+00:00","modifiedAt":"2026-10-08T15:51:50.406+00:00","affected":[{"ecosystem":"Vendor product","name":"traefik","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"traefik\",\n                    \"product\": \"traefik\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:golang/github.com/traefik/traefik/v3\",\n                    \"versions\": [\n                        {\n                            \"version\": \"3.7.0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\",\n                            \"lessThanOrEqual\": \"3.7.13\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","score":9.3,"severity":"CRITICAL"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://github.com/traefik/traefik/security/advisories/GHSA-cjr6-pf59-jq29","https://www.vulncheck.com/advisories/traefik-3.7.0-authentication-bypass-via-from-to-www-redirect"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-88877","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-88877","identifiers":["CVE-2026-88877"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-10T18:23:45.7727801+00:00","complete":true,"records":1773,"lastAttemptAt":"2026-11-10T18:23:45.7727801+00:00","lastSuccessAt":"2026-11-10T18:23:45.9579119+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:23:45.9579152+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-8859cf40d4337e24bd2f258cc7778fbad01bb24c79d057aaf34cf1dfc6f8917d-d220ab899e0e1c49e43094274f562c18c4a19b03898aec3feae1debdd31f6756","complete":true,"records":422212,"lastAttemptAt":"2026-11-10T18:21:27.6685178+00:00","lastSuccessAt":"2026-11-10T18:21:27.4920545+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:21:27.6685178+00:00","snapshotPublishedAt":"2026-11-10T17:27:33+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-acbb624a79c244aa868394151a25f053","complete":true,"records":13704,"lastAttemptAt":"2026-11-10T18:24:12.0072206+00:00","lastSuccessAt":"2026-11-10T18:24:12.001+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:24:12.001+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13758,"expectedIdentifiers":13758,"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":"2026-11-10T18:23:45.7727801+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-10T18:23:45.7727801+00:00","lastSuccessAt":"2026-11-10T18:23:45.9591411+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:23:45.9591459+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-4459456b8f8c43778c308d7de0a43211","complete":true,"records":13710,"lastAttemptAt":"2026-11-10T18:24:11.1447617+00:00","lastSuccessAt":"2026-11-10T18:24:11.141+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:24:11.141+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13758,"expectedIdentifiers":13758,"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-50a085e5b7a5d1546eabdb7e52fab85d658afa8554d3cf95a0891c49d83f2979","complete":true,"records":9935,"lastAttemptAt":"2026-11-10T18:23:45.7142755+00:00","lastSuccessAt":"2026-11-10T16:25:20.0114252+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:23:45.7142755+00:00","snapshotPublishedAt":"2026-11-10T16:18:10+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-26503967ae4379db8f374089589d6e03fb15bd31f820c9e992aaf93840c2236c","complete":true,"records":1971,"lastAttemptAt":"2026-11-10T18:21:27.7170016+00:00","lastSuccessAt":"2026-11-09T21:02:20.472473+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:21:27.7170016+00:00","snapshotPublishedAt":"2026-11-09T20:18:18+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-df497239f2f75af38e095cb498791dad4044a8a9a7f5f0ee6008bb732579ab9d","complete":true,"records":3081,"lastAttemptAt":"2026-11-10T18:23:45.7340645+00:00","lastSuccessAt":"2026-11-10T14:21:34.3717399+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:23:45.7340645+00:00","snapshotPublishedAt":"2026-11-10T14:18:07+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-5bab1d7e68ac802e78d67f5b951f7bcace0c45048e98b39b73b18376172e4b36","complete":true,"records":231619,"lastAttemptAt":"2026-11-10T18:23:45.5819776+00:00","lastSuccessAt":"2026-11-10T18:23:44.1117746+00:00","error":null,"lastVerifiedAt":"2026-11-10T18:23:45.5819776+00:00","snapshotPublishedAt":"2026-11-10T17:33:21+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}