What is CVE-2026-33496?

CVE-2026-33496 is a high-severity vulnerability in Ory Oathkeeper, classified under Authentication Bypass by Primary Weakness. CVSS score: 8.1/10. Published 2026-03-26.

How severe is CVE-2026-33496?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Ory Oathkeeper

CVE-2026-33496

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.

Published 2026-03-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.005 (41.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Ory Oathkeeper — versions < 26.2.0

Weakness classification (CWE)

References

github.com/ory/oathkeeper/security/advisories/GHSA-4mq7-pvjg-xp2r (Mitigation, Vendor Advisory)
github.com/ory/oathkeeper/commit/198a2bc82a99e0a77bd0ffe290cbdd5285a1b17c (Patch)

Frequently asked questions

What is CVE-2026-33496?: CVE-2026-33496 is a high-severity vulnerability in Ory Oathkeeper, classified under Authentication Bypass by Primary Weakness. CVSS score: 8.1/10. Published 2026-03-26.
How severe is CVE-2026-33496?: High severity. CVSS v3 base score is 8.1 out of 10.