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-2026-70493

CVE-2026-70493MEDIUM

open-webui open-webui — Open WebUI: Any authenticated user can stall a worker via a knowledge-search pattern that backtracks catastrophically

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   L   N  U  N  N  H    6.5   .0059   46.4     —

AFFECTED
  Product     Versions              Fixed
  open-webui  >= 0.9.6, < 0.11.0 –  —

TIMELINE
  Aug 4   Reserved by GitHub_M
  Aug 4   Published (CNA: GitHub_M)
  Sep 18  EXPLOIT PUBLISHED — CVE-2026-70493 (open-webui). Public exploit reference added.

CWE-1333 · CNA: GitHub_M · CVSS v3.1 · 4 references · NVD status: Analyzed

Description

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, the built-in knowledge search path in backend/open_webui/tools/knowledge_fs.py and backend/open_webui/tools/builtin.py let a chat participant choose a pattern used to grep knowledge files. Patterns containing regex metacharacters were compiled with Python's backtracking re engine and run against every line of every reachable file with no time limit, so a crafted pattern such as (x|x)*y and one matching uploaded file line can pin one CPU core and block the event loop. This causes availability impact for every other user of the affected worker. This issue is fixed in 0.11.0.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
August 4, 2026	Reserved	Reserved by GitHub_M
August 4, 2026	Published	Published (CNA: GitHub_M)
September 18, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-70493 (open-webui). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
open-webui	open-webui	—	>= 0.9.6, < 0.11.0	—

Weaknesses

CWE-1333

References (4)

https://github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9cb903e595 [Patch]
https://github.com/open-webui/open-webui/pull/27471 [Patch, Vendor Advisory]
https://github.com/open-webui/open-webui/releases/tag/v0.11.0 [Release Notes]
https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6 [Exploit, Patch, Vendor Advisory]

Authoritative record: CVE-2026-70493 at cve.org

Vendors: open-webui

Weaknesses: CWE-1333

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-70493 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.