Ory Oathkeeper has an authentication bypass by cache key confusion in github.com/ory/oathkeeper
Ory Oathkeeper has an authentication bypass by cache key confusion in github.com/ory/oathkeeper
02 / AFFECTED SOFTWARE
Affected packages
108 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
## Description Ory Oathkeeper is 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. ## Preconditions 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](https://www.ory.com/docs/oathkeeper/pipeline/authn#oauth2_introspection-configuration). An attacker has to have a way to gain a valid token for one of the configured introspection servers. ## Mitigation Ory Oathkeeper now 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.
Ory Oathkeeper has an authentication bypass by cache key confusion in github.com/ory/oathkeeper
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.
05 / REFERENCES
Further evidence
- https://github.com/ory/oathkeeper
- https://github.com/ory/oathkeeper/commit/198a2bc82a99e0a77bd0ffe290cbdd5285a1b17c
- https://github.com/ory/oathkeeper/security/advisories/GHSA-4mq7-pvjg-xp2r
- https://nvd.nist.gov/vuln/detail/CVE-2026-33496
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33496.json