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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-70493: 0.59% estimated exploitation activity in the next 30 days; percentile 48.36 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The built-in knowledge search tools let a chat participant choose the 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 anywhere on that path. A single crafted pattern and a single short line of matching text pin one CPU core for as long as the attacker wants, and because the search runs synchronously inside the event loop, that worker serves nobody else while it spins. Preconditions - Default configuration. The knowledge builtin tool group is enabled by default, and with ENABLEKBEXEC at its default of False the model is handed grepknowledgefiles, which is the affected path. - Any authenticated user, no elevated role and no workspace permission. - One file the attacker can read. USERPERMISSIONSCHATFILEUPLOAD defaults to true and a user always has read access to their own upload, so both halves of the input are…

Published by the source

4 Aug 2026, 20:56 UTC

Last modified by the source

4 Aug 2026, 20:56 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2f54-p244-32q6

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# Patch Next advisory brief: CVE-2026-70493

Advisory: Open WebUI: Any authenticated user can stall a worker via a knowledge-search pattern that backtracks catastrophically
IDs: CVE-2026-70493, GHSA-2f54-p244-32q6
Record: https://patchnext.com/advisories/cve-2026-70493 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: open-webui 0.11.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI open-webui: affected >= 0.9.6, < 0.11.0; fixed in 0.11.0

## Suggested inspection (read-only)
- `python -m pip show open-webui`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on open-webui.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2f54-p244-32q6 (GitHub-reviewed advisory GHSA-2f54-p244-32q6 lists affected ranges: PyPI open-webui >=0.9.6 <0.11.0)

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