Open WebUI: DNS Rebinding SSRF Bypass

Exploitation

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

CVSS

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

EPSS

• CVE-2026-54020: 0.25% estimated exploitation activity in the next 30 days; percentile 16.74 (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 Open WebUI vetted user-supplied URLs by resolving the hostname once and rejecting private, loopback and link-local addresses, then let the HTTP client resolve that hostname again at connect time. An attacker who controls the authoritative DNS for a hostname they submit can answer with a public address during the check and an internal one at connect, so the fetch reaches an address the check was meant to block. Every user-reachable fetch gated by that check was affected, and most of them hand the internal response back to the attacker. Preconditions - An account on the instance. No admin rights and no non-default configuration. - Control of the authoritative DNS for a hostname the attacker submits, serving a TTL of 0 and alternating answers. - One of the affected entry points: URL ingest for retrieval, an imageurl in a chat completion, image editing, or the OAuth profile-picture fetch. - The OAuth path additionally needs OAuth login configured and a picture claim…

Published by the source

4 Aug 2026, 20:38 UTC

Last modified by the source

4 Aug 2026, 21:07 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-h6x2-583h-x99r

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# Patch Next advisory brief: CVE-2026-54020

Advisory: Open WebUI: DNS Rebinding SSRF Bypass
IDs: CVE-2026-54020, GHSA-h6x2-583h-x99r
Record: https://patchnext.com/advisories/cve-2026-54020 (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 6.3)
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 <= 0.10.2; 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-h6x2-583h-x99r (GitHub-reviewed advisory GHSA-h6x2-583h-x99r lists affected ranges: PyPI open-webui >=0 <=0.10.2)

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