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Jenkins has a DNS rebinding vulnerability in WebSocket CLI origin validation

High severity GitHub Reviewed Published Mar 18, 2026 to the GitHub Advisory Database • Updated Mar 19, 2026

Package

maven org.jenkins-ci.main:jenkins-core (Maven)

Affected versions

>= 2.442, < 2.555

Patched versions

2.555

Description

Jenkins 2.442 through 2.554 (both inclusive), LTS 2.426.3 through LTS 2.541.2 (both inclusive) performs origin validation of requests made through the CLI WebSocket endpoint by computing the expected origin for comparison using the Host or X-Forwarded-Host HTTP request headers, making it vulnerable to DNS rebinding attacks that allow bypassing origin validation.

References

Published by the National Vulnerability Database Mar 18, 2026
Published to the GitHub Advisory Database Mar 18, 2026
Reviewed Mar 19, 2026
Last updated Mar 19, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(4th percentile)

Weaknesses

Origin Validation Error

The product does not properly verify that the source of data or communication is valid. Learn more on MITRE.

Reliance on Reverse DNS Resolution for a Security-Critical Action

The product performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname. Learn more on MITRE.

CVE ID

CVE-2026-33002

GHSA ID

GHSA-phhv-63fh-rrc8

Source code

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