CVE-2026-33495: Github.com/ory/oathkeeper Authentication Bypass Vulnerability
MODERATECVE-2026-33495 is a MODERATE (CVSS 6.5) authentication bypass vulnerability (CWE-862: Missing Authorization) affecting Github.com/ory/oathkeeper libraries in the Go ecosystem. The issue involves ory oathkeeper has an authentication bypass by usage of untrusted header. Remediation is available by upgrading affected packages to version 0.40.10-0.20260320084810-e9acca14a04d.
CVE-2026-33495 at a Glance
Security Impact
CVSS: 6.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N).
How to Fix CVE-2026-33495
To remediate this vulnerability, upgrade all affected Github.com/ory/oathkeeper dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/ory/oathkeeper to 0.40.10-0.20260320084810-e9acca14a04dRun the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/ory/oathkeeperHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-33495, inspect your project dependencies for Github.com/ory/oathkeeper:
inspect dependencies for github.com/ory/oathkeeperAnalyze the terminal output to locate any version of Github.com/ory/oathkeeper in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.40.10-0.20260320084810-e9acca14a04d), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. In Github.com/ory/oathkeeper, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-33495 Affected Github.com/ory/oathkeeper Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/ory/oathkeeper
|
Go |
< 0.40.10-0.20260320084810-e9acca14a04d
|
0.40.10-0.20260320084810-e9acca14a04d
|
References
Frequently Asked Questions
What is CVE-2026-33495?
Which Github.com/ory/oathkeeper versions are affected?
What version fixes CVE-2026-33495?
Is github.com/ory/oathkeeper affected?
What is the CVSS score of CVE-2026-33495?
What CWE is associated with CVE-2026-33495?
How can I check Go dependencies for CVE-2026-33495?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-vhr5-ggp3-qq85",
"modified" : "2026-03-27T20:58:41Z",
"published" : "2026-03-20T20:50:54Z",
"aliases" : [ "CVE-2026-33495" ],
"summary" : "Ory Oathkeeper has an authentication bypass by usage of untrusted header",
"details" : "## Description\n\nOry Oathkeeper is often deployed behind other components like CDNs, WAFs, or reverse proxies. Depending on the setup, another component might forward the request to the Oathkeeper proxy with a different protocol (http vs. https) than the original request. In order to properly match the request against the configured rules, Oathkeeper considers the `X-Forwarded-Proto` header when evaluating rules. The configuration option `serve.proxy.trust_forwarded_headers` (defaults to false) governs whether this and other `X-Forwarded-*` headers should be trusted. Oathkeeper did not properly respect this configuration, and would always consider the `X-Forwarded-Proto` header.\n\n## Preconditions\n\nIn order for an attacker to abuse this, an installation of Ory Oathkeeper needs to have distinct rules for HTTP and HTTPS requests. Also, the attacker needs to be able to trigger one but not the other rule. In this scenario, the attacker can send the same request but with the `X-Forwarded-Proto` header in order to trigger the other rule. We do not expect many configurations to meet these preconditions.\n\n## Mitigation\n\nIt is generally recommended to drop any unexpected headers as early as possible when a request is handled, e.g. in the WAF.\n\nOry Oathkeeper will correctly respect the `serve.proxy.trust_forwarded_headers` configuration going forward, thereby eliminating the attack scenario. We recommend upgrading to a fixed version even if the preconditions are not met.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/ory/oathkeeper"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.40.10-0.20260320084810-e9acca14a04d"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/ory/oathkeeper/security/advisories/GHSA-vhr5-ggp3-qq85"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33495"
}, {
"type" : "WEB",
"url" : "https://github.com/ory/oathkeeper/commit/e9acca14a04d246250557550065e4b4576525bd5"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/ory/oathkeeper"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-862" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-20T20:50:54Z",
"nvd_published_at" : "2026-03-26T18:16:30Z"
}
}