Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-87011

CVE-2026-87011HIGH

open-webui open-webui — Open WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0064   49.1     —

AFFECTED
  Product     Versions              Fixed
  open-webui  >= 0.9.0, < 0.11.1 –  —

TIMELINE
  Sep 8   Reserved by GitHub_M
  Sep 9   Published (CNA: GitHub_M)
  Sep 15  EXPLOIT PUBLISHED — CVE-2026-87011 (open-webui). Public exploit reference added.

CWE-405, CWE-770 · CNA: GitHub_M · CVSS v3.1 · 3 references · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
September 8, 2026	Reserved	Reserved by GitHub_M
September 9, 2026	Published	Published (CNA: GitHub_M)
September 15, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-87011 (open-webui). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
open-webui	open-webui	—	>= 0.9.0, < 0.11.1	—

Weaknesses

CWE-405 · CWE-770

References (3)

https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c [Patch]
https://github.com/open-webui/open-webui/releases/tag/v0.11.1 [Release Notes]
https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-87011 at cve.org

Vendors: open-webui

Weaknesses: CWE-405 · CWE-770

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-87011 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.