CVE-2026-87011

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-87011", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-09-08T16:44:23.783Z", "datePublished": "2026-09-09T20:54:26.207Z", "dateUpdated": "2026-09-14T13:42:35.435Z"}, "containers": {"cna": {"title": "Open WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout", "problemTypes": [{"descriptions": [{"cweId": "CWE-405", "lang": "en", "description": "CWE-405: Asymmetric Resource Consumption (Amplification)", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-770", "lang": "en", "description": "CWE-770: Allocation of Resources Without Limits or Throttling", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w"}, {"name": "https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c", "tags": ["x_refsource_MISC"], "url": "https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c"}, {"name": "https://github.com/open-webui/open-webui/releases/tag/v0.11.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/open-webui/open-webui/releases/tag/v0.11.1"}], "affected": [{"vendor": "open-webui", "product": "open-webui", "versions": [{"version": ">= 0.9.0, < 0.11.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-09T20:54:26.207Z"}, "descriptions": [{"lang": "en", "value": "Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.1, the unauthenticated POST /oauth/backchannel-logout handler in backend/open_webui/utils/oauth.py fetched the OIDC discovery document and signing keys before validating a submitted logout token. Each request repeated uncached network fetches, and the signing-key lookup blocked the async event loop, so requests carrying invalid tokens could stall the single-worker instance and amplify traffic to the identity provider when ENABLE_OAUTH_BACKCHANNEL_LOGOUT was enabled. This issue is fixed in version 0.11.1."}], "source": {"advisory": "GHSA-3g9q-v48f-hh9w", "discovery": "UNKNOWN"}}, "adp": [{"references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-14T13:41:36.439676Z", "id": "CVE-2026-87011", "options": [{"Exploitation": "poc"}, {"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": "2026-09-14T13:42:35.435Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-87011", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-09-08T16:44:23.783Z", "datePublished": "2026-09-09T20:54:26.207Z", "dateUpdated": "2026-09-14T13:42:35.435Z"}, "containers": {"cna": {"title": "Open WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout", "problemTypes": [{"descriptions": [{"cweId": "CWE-405", "lang": "en", "description": "CWE-405: Asymmetric Resource Consumption (Amplification)", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-770", "lang": "en", "description": "CWE-770: Allocation of Resources Without Limits or Throttling", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w"}, {"name": "https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c", "tags": ["x_refsource_MISC"], "url": "https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c"}, {"name": "https://github.com/open-webui/open-webui/releases/tag/v0.11.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/open-webui/open-webui/releases/tag/v0.11.1"}], "affected": [{"vendor": "open-webui", "product": "open-webui", "versions": [{"version": ">= 0.9.0, < 0.11.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-09T20:54:26.207Z"}, "descriptions": [{"lang": "en", "value": "Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.1, the unauthenticated POST /oauth/backchannel-logout handler in backend/open_webui/utils/oauth.py fetched the OIDC discovery document and signing keys before validating a submitted logout token. Each request repeated uncached network fetches, and the signing-key lookup blocked the async event loop, so requests carrying invalid tokens could stall the single-worker instance and amplify traffic to the identity provider when ENABLE_OAUTH_BACKCHANNEL_LOGOUT was enabled. This issue is fixed in version 0.11.1."}], "source": {"advisory": "GHSA-3g9q-v48f-hh9w", "discovery": "UNKNOWN"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-87011", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-14T13:41:36.439676Z"}}}], "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-14T13:42:24.066Z"}}]}}

{"affected": [{"affectedData": [{"product": "open-webui", "vendor": "open-webui", "versions": [{"status": "affected", "version": ">= 0.9.0, < 0.11.1"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*", "matchCriteriaId": "7E28CB04-D68C-4671-9F9B-511FA13EDB5C", "versionEndExcluding": "0.11.1", "versionStartIncluding": "0.9.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.1, the unauthenticated POST /oauth/backchannel-logout handler in backend/open_webui/utils/oauth.py fetched the OIDC discovery document and signing keys before validating a submitted logout token. Each request repeated uncached network fetches, and the signing-key lookup blocked the async event loop, so requests carrying invalid tokens could stall the single-worker instance and amplify traffic to the identity provider when ENABLE_OAUTH_BACKCHANNEL_LOGOUT was enabled. This issue is fixed in version 0.11.1."}], "id": "CVE-2026-87011", "lastModified": "2026-09-15T16:26:18.880", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-87011", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-09-14T13:41:36.439676Z", "version": "2.0.3"}}]}, "published": "2026-09-09T21:17:05.847", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c"}, {"source": "security-advisories@github.com", "tags": ["Release Notes"], "url": "https://github.com/open-webui/open-webui/releases/tag/v0.11.1"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-405"}, {"lang": "en", "value": "CWE-770"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0.9.0,0.11.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "open-webui", "source": "cna", "vendor": "open-webui"}, "product": "open-webui", "vendor": "open-webui"}], "created": "2026-09-09T23:00:08.442453+00:00", "updated": "2026-09-10T11:30:06.680156+00:00", "vendors": ["open-webui", "open-webui$PRODUCT$open-webui"]}