CVE-2026-33496 | ory oathkeeper up to 26.1.x oauth2_introspection improper validation of unsafe equivalence in input

VDB-353688 · CVE-2026-33496 · GCVE-0-2026-33496 ORY OATHKEEPER UP TO 26.1.X OAUTH2_INTROSPECTION IMPROPER VALIDATION OF UNSAFE EQUIVALENCE IN INPUT HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 7.0 $0-$5k 2.35+ Summaryinfo A vulnerability was found in ory oathkeeper up to 26.1.x. It has been declared as critical. Impacted is the function oauth2_introspection. The manipulation results in improper validation of unsafe equivalence in input. This vulnerability was named CVE-2026-33496. The attack may be performed from remote. There is no available exploit. It is recommended to upgrade the affected component. Detailsinfo A vulnerability was found in ory oathkeeper up to 26.1.x. It has been classified as critical. Affected is the function oauth2_introspection. The manipulation with an unknown input leads to a improper validation of unsafe equivalence in input vulnerability. CWE is classifying the issue as CWE-1289. The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes: 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. The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-33496 since 03/20/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are known technical details, but no exploit is available. Upgrading to version 26.2.0 eliminates this vulnerability. Productinfo Vendor ory Name oathkeeper Version 26.0 26.1 Website Product: https://github.com/ory/oathkeeper/ CPE 2.3info 🔒 🔒 CPE 2.2info 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 7.2 VulDB Meta Temp Score: 7.0 VulDB Base Score: 6.3 VulDB Temp Score: 6.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 8.1 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Improper validation of unsafe equivalence in input CWE: CWE-1289 / CWE-20 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: oathkeeper 26.2.0 Timelineinfo 03/20/2026 CVE reserved 03/26/2026 +6 days Advisory disclosed 03/26/2026 +0 days VulDB entry created 03/26/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: github.com Status: Confirmed CVE: CVE-2026-33496 (🔒) GCVE (CVE): GCVE-0-2026-33496 GCVE (VulDB): GCVE-100-353688 Entryinfo Created: 03/26/2026 19:04 Changes: 03/26/2026 19:04 (63) Complete: 🔍 Cache ID: 99:054:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸