CVE-2026-33496Network attack vector

Authentication bypass via cross-server token cache confusion

Published Mar 26, 2026 · Updated Mar 26, 2026

Authentication bypass in Ory Oathkeeper before 26.2.0 allows remote authenticated users to access protected resources with a mismatched token. The oauth2_introspection authenticator keys cached results only by token, so a result from one introspection URL is reused by another. Exploitation requires caching, at least two introspection servers that accept different tokens, and a valid token for one server; successful reuse grants access assigned by the other rule.

CVSS severity8.1
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Ory Oathkeeper before 26.2.0 allows remote authenticated users to access protected resources with a mismatched token. The oauth2_introspection authenticator keys cached results only by token, so a result from one introspection URL is reused by another. Exploitation requires caching, at least two introspection servers that accept different tokens, and a valid token for one server; successful reuse grants access assigned by the other rule.

The record

CVE
CVE-2026-33496
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
Ory
Product
Oathkeeper
Classifications
CWE-305, CWE-1289, T1550
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 26.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Ory · Oathkeeperversion=< 26.2.0

Published CVSS scores

8.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-305Authentication Bypass by Primary Weakness
CWE-1289Improper Validation of Unsafe Equivalence in Input
T1550Use Alternate Authentication Material

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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