{"id":"CVE-2026-107566","revision":null,"records":[{"revision":"788b9317a31745809fd034c31fea5201","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-107566","aliases":[],"title":"Missing Authorization in hMailServer","description":"Missing authorization in the Sieve editheader action (6.2.22 through 6.3.6) and in the mail-rule Set header value action (6.0.0 through 6.3.6) of Progressive Robot hMailServer allows an authenticated user to make the server send mail as any address, DKIM-signed where the address is at a domain the server signs for. A Sieve script's editheader (addheader/deleteheader) could add or delete any header field except Received and Return-Path, and the server applies a script's header edits before it queues a redirect, so the redirected copy is sent as the script left it. The server signs a message's first delivery pass as the domain named in its From header wherever it signs DKIM for that domain and the message carries no signature of it. A script could therefore delete and re-add From - another account's address, or anyone's at a hosted domain - and redirect, so the server sent the message in that name and, for a hosted domain, signed it with that domain's DKIM key, a forgery aligned to pass the domain's DMARC; or, where another sender's domain is one the server signs for, delete the DKIM-Signature that sender's message arrived with, alter a field, and redirect, so the server re-signed the altered message as that sender's domain. editheader placed no restriction on From, Sender, Resent-From, Resent-Sender or DKIM-Signature. The editheader action was introduced in 6.2.22. In the mail-rule engine, a domain's or an account's rule's Set header value action could likewise set From, Sender, Resent-From, Resent-Sender or DKIM-Signature ahead of a forward or a copy, whoever the rule belonged to, so that an account acting on its own rules over COM, a domain administrator, or an API key confined to a domain (over the REST API from 6.3.4) could have the server forward or copy a message in the name of any address, signed, where that address is at a domain the server hosts with DKIM signing enabled, with that domain's key.","state":0,"publishedAt":"2026-10-19T15:34:27.491+00:00","modifiedAt":"2026-10-20T19:25:48.56+00:00","affected":[{"ecosystem":"Vendor product","name":"hMailServer","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Progressive Robot Ltd\",\n                    \"product\": \"hMailServer\",\n                    \"repo\": \"https://gitlab.com/hmailserver/hmailserver\",\n                    \"versions\": [\n                        {\n                            \"version\": \"6.0.0\",\n                            \"status\": \"affected\",\n                            \"lessThanOrEqual\": \"6.3.6\",\n                            \"versionType\": \"semver\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","score":6.5,"severity":"MEDIUM"}],"references":["https://gitlab.com/hmailserver/hmailserver/-/work_items/83","https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.7"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-107566","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-107566","identifiers":["CVE-2026-107566"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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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-86f25219fb644e6286aef55d85e25bf2","complete":true,"records":13654,"lastAttemptAt":"2026-11-08T12:05:08.2403712+00:00","lastSuccessAt":"2026-11-08T11:08:04.005+00:00","error":null,"lastVerifiedAt":"2026-11-08T11:08:04.005+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":"2026-11-08T12:04:37.5111605+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-08T12:04:37.5111605+00:00","lastSuccessAt":"2026-11-08T12:04:37.7247541+00:00","error":null,"lastVerifiedAt":"2026-11-08T12:04:37.7247552+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-c8ab24cce7724539b5148423668d4a8d","complete":false,"records":13666,"lastAttemptAt":"2026-11-08T12:05:07.5124328+00:00","lastSuccessAt":"2026-11-08T12:05:07.509+00:00","error":null,"lastVerifiedAt":"2026-11-08T12:05:07.509+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13685,"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":"2026-11-08T12:04:37.4138776+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-08T12:04:37.4138776+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":"2026-11-08T12:04:37.186742+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-08T12:04:37.186742+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":"2026-11-08T12:04:37.4417198+00:00","lastSuccessAt":"2026-11-08T11:07:12.1927025+00:00","error":null,"lastVerifiedAt":"2026-11-08T12:04:37.4417198+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":"2026-11-08T12:04:37.3024645+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-08T12:04:37.3024645+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}