{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-27651", "assignerOrgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "state": "PUBLISHED", "assignerShortName": "f5", "dateReserved": "2026-03-18T16:06:38.454Z", "datePublished": "2026-03-24T14:13:27.295Z", "dateUpdated": "2026-03-24T15:14:13.220Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "shortName": "f5", "dateUpdated": "2026-03-24T14:22:35.756Z"}, "title": "NGINX ngx_mail_auth_http_module vulnerability", "datePublic": "2026-03-24T14:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-476", "description": "CWE-476 NULL Pointer Dereference", "type": "CWE"}]}], "affected": [{"vendor": "F5", "product": "NGINX Open Source", "modules": ["ngx_mail_auth_http_module"], "versions": [{"status": "affected", "version": "1.29.0", "lessThan": "1.29.7", "versionType": "semver"}, {"status": "affected", "version": "0.5.15", "lessThan": "1.28.3", "versionType": "semver"}], "defaultStatus": "unknown"}, {"vendor": "F5", "product": "NGINX Plus", "modules": ["ngx_mail_auth_http_module"], "versions": [{"status": "affected", "version": "R36", "lessThan": "R36 P3", "versionType": "custom"}, {"status": "affected", "version": "R35", "lessThan": "R35 P2", "versionType": "custom"}, {"status": "affected", "version": "R34", "lessThan": "*", "versionType": "custom"}, {"status": "affected", "version": "R33", "lessThan": "*", "versionType": "custom"}, {"status": "affected", "version": "R32", "lessThan": "R32 P5", "versionType": "custom"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "When the ngx_mail_auth_http_module\u00a0module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<span style=\"background-color: rgb(255, 255, 255);\">When the </span><strong>ngx_mail_auth_http_module</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header.</span> Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}]}], "references": [{"url": "https://my.f5.com/manage/s/article/K000160383", "tags": ["vendor-advisory"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 7.5, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"version": "4.0", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subAvailabilityImpact": "NONE", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "baseSeverity": "HIGH", "baseScore": 8.7, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}}], "credits": [{"lang": "en", "value": "F5 acknowledges Arkadi Vainbrand for bringing this issue to our attention and following the highest standards of coordinated disclosure.", "type": "reporter"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "F5 SIRTBot v1.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-03-24T15:02:03.137056Z", "id": "CVE-2026-27651", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-24T15:14:13.220Z"}}]}}

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