Cyber Resilience

CVE-2026-33496

Auth Bypass in Ory Oathkeeper ≤ 26.2.0

Published
26 March 2026
Modified
07 April 2026
Patch / advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0038 31th percentile
Risk Priority 59 floored blend · peak EPSS

Summary

CVE-2026-33496 is a high-severity Authentication Bypass by Primary Weakness (CWE-305) vulnerability in Ory Oathkeeper. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 31th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to IA-2 (Identification and Authentication (Organizational Users)) and IA-8 (Identification and Authentication (Non-organizational Users)) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-33496 is an authentication bypass vulnerability in ORY Oathkeeper, an Identity & Access Proxy (IAP) and Access Control Decision API that authorizes HTTP requests based on Access Rules. Versions prior to 26.2.0 are affected due to cache key confusion in the oauth2_introspection authenticator, which fails to distinguish tokens validated against different introspection URLs.

An attacker can exploit this vulnerability if Ory Oathkeeper is configured with multiple oauth2_introspection authenticator servers—each accepting different tokens—and caching is enabled for these authenticators. The attacker must first obtain a valid token for one of the configured introspection servers to prime the cache. They can then reuse the same token to authenticate against rules that rely on a different introspection server, bypassing authentication. This leads to high confidentiality and integrity impacts, with a CVSS score of 8.1 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N), associated with CWEs 305 and 1289.

The Ory Oathkeeper security advisory (GHSA-4mq7-pvjg-xp2r) and related commit recommend updating to version 26.2.0, which includes the introspection server URL in the cache key to prevent token confusion. As an interim mitigation, disable caching for oauth2_introspection authenticators.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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`…

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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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-33494Same product: Ory Oathkeeper
CVE-2026-33495Same product: Ory Oathkeeper
CVE-2026-33503Same vendor: Ory
CVE-2026-33504Same vendor: Ory
CVE-2026-33505Same vendor: Ory
CVE-2026-0869Shared CWE-305
CVE-2023-36497Shared CWE-305
CVE-2024-42513Shared CWE-305
CVE-2025-52996Shared CWE-305
CVE-2025-46750Shared CWE-305

Affected Assets

ory
oathkeeper
≤ 26.2.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V5.2.2
  • V9.1.3
  • V10.4.6
  • V2.2.2

Mitigating Controls (NIST 800-53 r5) AI

Requires unique identification and authentication of users, structurally blocking bypass of the mechanism.

Requires unique identification and authentication of non-organizational users, blocking bypass paths.

SI-10 requires validity checks on information inputs, directly stopping unsafe equivalence validation failures for identifiers and references.

Enforces approved authorizations so a bypass weakness cannot be exploited to reach resources.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 full match
prevents

Secure development practices throughout the SDLC prevent the primary weaknesses that enable authentication bypass.

PR.AA-03 mostly match
prevents

Strong authentication mechanisms and policy enforcement directly reduce bypass opportunities arising from implementation flaws.

ID.RA-01 partial match
prevents

Identifying and recording vulnerabilities catches the primary weaknesses that allow authentication bypass.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect authentication bypass conditions before deployment.

prevents

Secure development lifecycle reduces likelihood of introducing bypass flaws during implementation.

prevents

Application security requirements can mandate input validation rules that prevent unsafe equivalence checks.

prevents

Secure architecture principles include proper input validation and canonicalization to avoid unsafe equivalence.

prevents

Secure coding practices help prevent the primary weakness that enables authentication bypass.

mitigates

Information access restriction complements authentication by limiting what can be reached even if bypass occurs.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Ubuntu 22.04 (1 rule)
  • V-260470 Ubuntu 22.04 LTS, when booted, must require authentication upon booting into single-user and maintenance modes. prevents CWE-305
Ubuntu 24.04 (1 rule)
  • V-270675 Ubuntu 24.04 LTS when booted must require authentication upon booting into single-user and maintenance modes. prevents CWE-305

References