Ory Oathkeeper has an authentication bypass by usage of untrusted header

Exploitation

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

CVSS

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

EPSS

• CVE-2026-33495: 0.24% estimated exploitation activity in the next 30 days; percentile 15.53 (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.

Description Ory Oathkeeper is often deployed behind other components like CDNs, WAFs, or reverse proxies. Depending on the setup, another component might forward the request to the Oathkeeper proxy with a different protocol (http vs. https) than the original request. In order to properly match the request against the configured rules, Oathkeeper considers the X-Forwarded-Proto header when evaluating rules. The configuration option serve.proxy.trustforwardedheaders (defaults to false) governs whether this and other X-Forwarded- headers should be trusted. Oathkeeper did not properly respect this configuration, and would always consider the X-Forwarded-Proto header. Preconditions In order for an attacker to abuse this, an installation of Ory Oathkeeper needs to have distinct rules for HTTP and HTTPS requests. Also, the attacker needs to be able to trigger one but not the other rule. In this scenario, the attacker can send the same request but with the X-Forwarded-Proto header in order…

Published by the source

20 Mar 2026, 20:50 UTC

Last modified by the source

27 Mar 2026, 20:58 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vhr5-ggp3-qq85

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# Patch Next advisory brief: CVE-2026-33495

Advisory: Ory Oathkeeper has an authentication bypass by usage of untrusted header
IDs: CVE-2026-33495, GHSA-vhr5-ggp3-qq85
Record: https://patchnext.com/advisories/cve-2026-33495 (revision 1, source checked 26 Oct 2026, 15:18 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: github.com/ory/oathkeeper 0.40.10-0.20260320084810-e9acca14a04d. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/ory/oathkeeper: affected < 0.40.10-0.20260320084810-e9acca14a04d; fixed in 0.40.10-0.20260320084810-e9acca14a04d

## Suggested inspection (read-only)
- Go github.com/ory/oathkeeper: check the installed version with your package manager.

## 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 github.com/ory/oathkeeper.
- 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-vhr5-ggp3-qq85 (GitHub-reviewed advisory GHSA-vhr5-ggp3-qq85 lists affected ranges: Go github.com/ory/oathkeeper >=0 <0.40.10-0.20260320084810-e9acca14a04d)

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