CVE-2026-33496: CWE-1289: Improper Validation of Unsafe Equivalence in Input in 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.
AI Analysis
Technical Summary
CVE-2026-33496 affects ORY Oathkeeper, an Identity & Access Proxy and Access Control Decision API. The vulnerability arises from improper validation of unsafe equivalence in input, specifically in the oauth2_introspection authenticator cache. Tokens validated against different introspection URLs are cached under the same key, allowing an attacker who has a valid token for one introspection server to bypass authentication on rules using other introspection servers. This occurs when multiple oauth2_introspection authenticators with caching enabled are configured. The issue is resolved in version 26.2.0 by incorporating the introspection server URL into the cache key, preventing token confusion.
Potential Impact
An attacker with a valid token for one configured introspection server can bypass authentication for other introspection servers by exploiting the cache key confusion. This leads to unauthorized access with high confidentiality and integrity impact, as indicated by the CVSS score of 8.1. There is no known exploitation in the wild at this time.
Mitigation Recommendations
A fixed version of ORY Oathkeeper is available starting from version 26.2.0, which addresses the vulnerability by including the introspection server URL in the cache key. Users should update to version 26.2.0 or later. If upgrading immediately is not feasible, it is recommended to disable caching for oauth2_introspection authenticators to prevent exploitation.
CVE-2026-33496: CWE-1289: Improper Validation of Unsafe Equivalence in Input in ory oathkeeper
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-33496 affects ORY Oathkeeper, an Identity & Access Proxy and Access Control Decision API. The vulnerability arises from improper validation of unsafe equivalence in input, specifically in the oauth2_introspection authenticator cache. Tokens validated against different introspection URLs are cached under the same key, allowing an attacker who has a valid token for one introspection server to bypass authentication on rules using other introspection servers. This occurs when multiple oauth2_introspection authenticators with caching enabled are configured. The issue is resolved in version 26.2.0 by incorporating the introspection server URL into the cache key, preventing token confusion.
Potential Impact
An attacker with a valid token for one configured introspection server can bypass authentication for other introspection servers by exploiting the cache key confusion. This leads to unauthorized access with high confidentiality and integrity impact, as indicated by the CVSS score of 8.1. There is no known exploitation in the wild at this time.
Mitigation Recommendations
A fixed version of ORY Oathkeeper is available starting from version 26.2.0, which addresses the vulnerability by including the introspection server URL in the cache key. Users should update to version 26.2.0 or later. If upgrading immediately is not feasible, it is recommended to disable caching for oauth2_introspection authenticators to prevent exploitation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-20T16:59:08.887Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 69c570d8f4197a8e3bef1f0a
Added to database: 3/26/2026, 5:46:00 PM
Last enriched: 4/3/2026, 1:12:23 PM
Last updated: 5/9/2026, 2:11:58 PM
Views: 57
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