CVE-2026-91926

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-91926", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-09-15T10:53:12.456Z", "datePublished": "2026-09-15T11:49:10.516Z", "dateUpdated": "2026-11-06T19:56:33.639Z"}, "containers": {"cna": {"title": "Gss-ntlmssp: gss-ntlmssp: memory leak in ntlm_decode_target_info via duplicated av_pair entries in ntlm challenge", "metrics": [{"other": {"content": {"value": "Low", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 3.7, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info parser when a crafted NTLM CHALLENGE message contains duplicated string-valued AV_PAIR entries. The parser allocates memory for each string value but does not free the previous allocation when the same AV_PAIR type appears more than once, leaking the earlier allocation. A malicious or man-in-the-middle server can exploit this to cause gradual memory exhaustion on the client during NTLM authentication, leading to a denial of service."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "gssntlmssp", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:enterprise_linux:8"]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-91926", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2533698", "name": "RHBZ#2533698", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-09-15T00:00:00.000Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-401", "description": "Missing Release of Memory after Effective Lifetime", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-401: Missing Release of Memory after Effective Lifetime", "workarounds": [{"lang": "en", "value": "No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, or stability."}], "timeline": [{"lang": "en", "time": "2026-09-11T00:15:46.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-09-15T00:00:00.000Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank Chase Bevan-Thomas (cbev0x) (Independent security researcher) for reporting this issue."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-11-06T19:56:33.639Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-17T14:24:14.247594Z", "id": "CVE-2026-91926", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"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": "2026-09-17T14:24:37.383Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-91926", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-17T14:24:14.247594Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-17T14:24:27.860Z"}}], "cna": {"title": "Gss-ntlmssp: gss-ntlmssp: memory leak in ntlm_decode_target_info via duplicated av_pair entries in ntlm challenge", "credits": [{"lang": "en", "value": "Red Hat would like to thank Chase Bevan-Thomas (cbev0x) (Independent security researcher) for reporting this issue."}], "metrics": [{"other": {"type": "Red Hat severity rating", "content": {"value": "Low", "namespace": "https://access.redhat.com/security/updates/classification/"}}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.7, "attackVector": "NETWORK", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "LOW", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}], "affected": [{"cpes": ["cpe:/a:redhat:enterprise_linux:8"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "packageName": "gssntlmssp", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}], "timeline": [{"lang": "en", "time": "2026-09-11T00:15:46.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-09-15T00:00:00.000Z", "value": "Made public."}], "datePublic": "2026-09-15T00:00:00.000Z", "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-91926", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2533698", "name": "RHBZ#2533698", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "workarounds": [{"lang": "en", "value": "No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, or stability."}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info parser when a crafted NTLM CHALLENGE message contains duplicated string-valued AV_PAIR entries. The parser allocates memory for each string value but does not free the previous allocation when the same AV_PAIR type appears more than once, leaking the earlier allocation. A malicious or man-in-the-middle server can exploit this to cause gradual memory exhaustion on the client during NTLM authentication, leading to a denial of service."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-401", "description": "Missing Release of Memory after Effective Lifetime"}]}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-11-06T19:56:33.639Z"}, "x_redhatCweChain": "CWE-401: Missing Release of Memory after Effective Lifetime"}}, "cveMetadata": {"cveId": "CVE-2026-91926", "state": "PUBLISHED", "dateUpdated": "2026-11-06T19:56:33.639Z", "dateReserved": "2026-09-15T10:53:12.456Z", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "datePublished": "2026-09-15T11:49:10.516Z", "assignerShortName": "redhat"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:8"], "defaultStatus": "affected", "packageName": "gssntlmssp", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat"}], "source": "secalert@redhat.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info parser when a crafted NTLM CHALLENGE message contains duplicated string-valued AV_PAIR entries. The parser allocates memory for each string value but does not free the previous allocation when the same AV_PAIR type appears more than once, leaking the earlier allocation. A malicious or man-in-the-middle server can exploit this to cause gradual memory exhaustion on the client during NTLM authentication, leading to a denial of service."}], "id": "CVE-2026-91926", "lastModified": "2026-11-06T20:17:28.823", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 3.7, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 1.4, "source": "secalert@redhat.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-91926", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-09-17T14:24:14.247594Z", "version": "2.0.3"}}]}, "published": "2026-09-15T12:17:54.500", "references": [{"source": "secalert@redhat.com", "url": "https://access.redhat.com/security/cve/CVE-2026-91926"}, {"source": "secalert@redhat.com", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2533698"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-401"}], "source": "secalert@redhat.com", "type": "Secondary"}]}

{"acknowledgement": "Red Hat would like to thank Chase Bevan-Thomas (cbev0x) (Independent security researcher) for reporting this issue.", "bugzilla": {"description": "gss-ntlmssp: gss-ntlmssp: memory leak in ntlm_decode_target_info via duplicated AV_PAIR entries in NTLM CHALLENGE", "id": "2533698", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2533698"}, "csaw": false, "cvss3": {"cvss3_base_score": "3.7", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L", "status": "draft"}, "cwe": "CWE-401", "details": ["A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info parser when a crafted NTLM CHALLENGE message contains duplicated string-valued AV_PAIR entries. The parser allocates memory for each string value but does not free the previous allocation when the same AV_PAIR type appears more than once, leaking the earlier allocation. A malicious or man-in-the-middle server can exploit this to cause gradual memory exhaustion on the client during NTLM authentication, leading to a denial of service."], "mitigation": {"lang": "en:us", "value": "No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, or stability."}, "name": "CVE-2026-91926", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "gssntlmssp", "product_name": "Red Hat Enterprise Linux 8"}], "public_date": "2026-09-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-91926\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-91926"], "statement": "This vulnerability is rated as Low severity because exploitation requires the attacker to control or impersonate the NTLM server (or hold a man-in-the-middle position), and the resulting memory leak is bounded and gradual, requiring sustained repeated authentications to produce meaningful resource exhaustion. The vulnerability only affects the NTLM client (initiator) path; the server (acceptor) path is not affected. Red Hat Enterprise Linux 8 ships gssntlmssp and is affected. gssntlmssp was removed from RHEL 9 and later releases, so those products are not affected.", "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Red Hat Enterprise Linux 8", "source": "cna", "vendor": "Red Hat"}, "product": "enterprise_linux", "vendor": "red_hat"}, {"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Red Hat Enterprise Linux 8", "source": "cna", "vendor": "Red Hat"}, "product": "enterprise_linux", "vendor": "redhat"}], "created": "2026-09-16T05:15:19.335850+00:00", "updated": "2026-11-10T22:45:02.600236+00:00", "vendors": ["red_hat", "red_hat$PRODUCT$enterprise_linux", "redhat", "redhat$PRODUCT$enterprise_linux"]}