{"api_version":"1","generated_at":"2026-10-21T17:40:13+00:00","cve":"CVE-2026-114473","urls":{"html":"https://cve.report/CVE-2026-114473","api":"https://cve.report/api/cve/CVE-2026-114473.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-114473","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-114473"},"summary":{"title":"Incorrect Authorization in hMailServer","description":"Incorrect authorization in the Sender Rewriting Scheme (SRS) of Progressive Robot hMailServer 6.2.1 through 6.3.6 allows a remote attacker to relay mail through the server to outside addresses. With SRS enabled, the server rewrites the envelope sender of mail it forwards to a signed SRS address at the forwarding domain, and passes a bounce to that address back to the original sender; but it took every message to a valid SRS address, whatever its sender, as delivery to a local recipient, so the relay rules and the SMTP authentication they require were not applied, and the message was delivered to the outside address the SRS address encodes. Anyone holding a valid SRS address of the server, such as the recipient of a forwarded message, could have the server relay mail to the address it encodes for 21 days, and an account holder whose account forwards to an outside mailbox could obtain one for any address. 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Until then, turn SRS off (SRSEnabled=0, the default).","time":"","lang":"en"}],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Upstream hMailServer, whose public pull request 649 fixed the same flaw in its own SRS code; found and fixed in this fork by the hMailServer project's triage of it (Progressive Robot Ltd)","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"hMailServer","repo":"https://gitlab.com/hmailserver/hmailserver","vendor":"Progressive Robot Ltd","versions":[{"lessThanOrEqual":"6.3.6","status":"affected","version":"6.2.1","versionType":"semver"}]}],"credits":[{"lang":"en","type":"finder","value":"Upstream hMailServer, whose public pull request 649 fixed the same flaw in its own SRS code; found and fixed in this fork by the hMailServer project's triage of it (Progressive Robot Ltd)"}],"descriptions":[{"lang":"en","value":"Incorrect authorization in the Sender Rewriting Scheme (SRS) of Progressive Robot hMailServer 6.2.1 through 6.3.6 allows a remote attacker to relay mail through the server to outside addresses. With SRS enabled, the server rewrites the envelope sender of mail it forwards to a signed SRS address at the forwarding domain, and passes a bounce to that address back to the original sender; but it took every message to a valid SRS address, whatever its sender, as delivery to a local recipient, so the relay rules and the SMTP authentication they require were not applied, and the message was delivered to the outside address the SRS address encodes. Anyone holding a valid SRS address of the server, such as the recipient of a forwarded message, could have the server relay mail to the address it encodes for 21 days, and an account holder whose account forwards to an outside mailbox could obtain one for any address. SRS is off by default."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-863","description":"CWE-863: Incorrect Authorization","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-10-21T15:12:05.843Z","orgId":"ceab7361-8a18-47b1-92ba-4d7d25f6715a","shortName":"GitLab"},"references":[{"url":"https://gitlab.com/hmailserver/hmailserver/-/work_items/94"},{"url":"https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.7"}],"solutions":[{"lang":"en","value":"Upgrade to hMailServer 6.3.7, which takes only a bounce (a null reverse-path) to an SRS address as local delivery and holds any other message to it to the relay rules: where they refuse it, the transaction is refused at DATA or BDAT, and a recipient named after such an address in the same transaction is answered 452 4.5.3. Until then, turn SRS off (SRSEnabled=0, the default)."}],"title":"Incorrect Authorization in hMailServer"}},"cveMetadata":{"assignerOrgId":"ceab7361-8a18-47b1-92ba-4d7d25f6715a","assignerShortName":"GitLab","cveId":"CVE-2026-114473","datePublished":"2026-10-21T15:12:05.843Z","dateReserved":"2026-10-21T15:11:15.857Z","dateUpdated":"2026-10-21T15:12:05.843Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-21 16:17:34","lastModifiedDate":"2026-10-21 16:17:34","problem_types":["CWE-863","CWE-863 CWE-863: Incorrect Authorization"],"metrics":{"cvssMetricV31":[{"source":"cve@gitlab.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","baseScore":5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":3.1,"impactScore":1.4}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"114473","Ordinal":"1","Title":"Incorrect Authorization in hMailServer","CVE":"CVE-2026-114473","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"114473","Ordinal":"1","NoteData":"Incorrect authorization in the Sender Rewriting Scheme (SRS) of Progressive Robot hMailServer 6.2.1 through 6.3.6 allows a remote attacker to relay mail through the server to outside addresses. With SRS enabled, the server rewrites the envelope sender of mail it forwards to a signed SRS address at the forwarding domain, and passes a bounce to that address back to the original sender; but it took every message to a valid SRS address, whatever its sender, as delivery to a local recipient, so the relay rules and the SMTP authentication they require were not applied, and the message was delivered to the outside address the SRS address encodes. Anyone holding a valid SRS address of the server, such as the recipient of a forwarded message, could have the server relay mail to the address it encodes for 21 days, and an account holder whose account forwards to an outside mailbox could obtain one for any address. SRS is off by default.","Type":"Description","Title":"Incorrect Authorization in hMailServer"}]}}}