CVE-2026-33496 is a high-severity (CVSS 8.1) CWE-305 vulnerability in github.com/ory/oathkeeper. A fix is available for github.com/ory/oathkeeper — see the affected versions and patch details below.
Ory Oathkeeper has an authentication bypass by cache key confusion
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33496.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-33496 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/ory/oathkeeperReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/ory/oathkeeper | all versions | 0.40.10-0.20260320084801-198a2bc82a99go get github.com/ory/oathkeeper@v0.40.10-0.20260320084801-198a2bc82a99 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ory/oathkeeper, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/ory/oathkeeper to 0.40.10-0.20260320084801-198a2bc82a99 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33496 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33496 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-33496. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-33496 in your dependencies?
O3 Security finds CVE-2026-33496 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.