CVE-2026-87011

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 70% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
30%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 15, 2026

Advisory Details (3)

Auto-updated Sep 9, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

v0.11.1

Patch available: open-webui/open-webui v0.11.1

https://github.com/open-webui/open-webui/releases/tag/v0.11.1
github_commit

commit aeda6ff13a25 (open-webui/open-webui)

Fix landed in open-webui/open-webui commit aeda6ff13a25 — awaiting tagged release

https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c
github Patch Available🟡 PoC Available

Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout · Advisory · open-webui/open-webui · GitHub

Affected: 0.11.1. The handler now resolves both the discovery document and the signing keys

https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w

Vendor Advisories for CVE-2026-87011(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
open-webui0.10.0 ... 0.9.6 (11 versions)0.11.1—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 15× in last 7d / 21× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 21:20 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 20:14 UTCEG score recompute
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-16 18:11 UTCEG score recompute
  6. 2026-09-16 14:09 UTCEPSS rescore
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 15:37 UTCEG score recompute
  9. 2026-09-15 03:12 UTCEPSS rescore
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-15 03:03 UTCEG score recompute
  12. 2026-09-14 14:30 UTCEG score recompute
  13. 2026-09-14 13:50 UTCEG score recompute
  14. 2026-09-13 18:21 UTCEG score recompute
  15. 2026-09-12 17:15 UTCEG score recompute
  16. 2026-09-11 16:07 UTCEG score recompute
  17. 2026-09-11 14:53 UTCEPSS rescore
  18. 2026-09-11 14:53 UTCEPSS rescore
  19. 2026-09-09 21:30 UTCEG score recompute
  20. 2026-09-09 21:00 UTCEG score recompute
  21. 2026-09-09 20:59 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-87011?
CVE-2026-87011 is a high vulnerability published on September 9, 2026. 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/openwebui/utils/oauth.py fetched the OIDC discovery document and signing keys before validating a submitted logout…
When was CVE-2026-87011 disclosed?
CVE-2026-87011 was first published in the National Vulnerability Database on September 9, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87011 actively exploited?
CVE-2026-87011 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 70.4% of all scored CVEs.
What is the CVSS score of CVE-2026-87011?
CVE-2026-87011 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-87011?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-87011, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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