CVE-2026-53437: Jenkins core Jenkins Open Redirect Through Newline/Tab Vulnerability

MODERATE
Advisory Identifier: GHSA-463r-5m89-4xfr
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CVSS 4.3
CWE-601
Published
Advisory Summary

CVE-2026-53437 is a MODERATE (CVSS 4.3) jenkins open redirect through newline/tab vulnerability (CWE-601: URL Redirection to Untrusted Site ('Open Redirect')) affecting Jenkins core libraries in the Maven ecosystem. The issue involves jenkins open redirect through newline/tab characters in redirect url. Remediation is available by upgrading affected packages to version 2.555.3, 2.568.

CVE-2026-53437 at a Glance

CVE Identifier CVE-2026-53437
GHSA Identifier GHSA-463r-5m89-4xfr
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-601: URL Redirection to Untrusted Site ('Open Redirect')
Affected Product Jenkins core
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 4.3

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:R/S:U/C:N/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-53437

To remediate this vulnerability, upgrade all affected Jenkins core dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.jenkins-ci.main:jenkins-core fixed: 2.555.3 
<dependency>
    <groupId>org.jenkins-ci.main</groupId>
    <artifactId>jenkins-core</artifactId>
    <version>2.555.3</version>
</dependency>
org.jenkins-ci.main:jenkins-core fixed: 2.568 
<dependency>
    <groupId>org.jenkins-ci.main</groupId>
    <artifactId>jenkins-core</artifactId>
    <version>2.568</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.jenkins-ci.main

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-53437, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.jenkins-ci.main

Analyze the terminal output to locate any version of Jenkins core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.555.3), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.jenkins-ci.main command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-601: URL Redirection to Untrusted Site ('Open Redirect'), where the web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect. In Jenkins core, 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

Jenkins 2.567 and earlier, LTS 2.555.2 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins when it contains tab or newline characters between `//`, allowing attackers to perform phishing attacks.

CVE-2026-53437 Affected Jenkins core Versions

2 component(s)
Fixed Versions:
2.555.32.568
Product / Package Ecosystem Affected Versions Fixed Version
org.jenkins-ci.main:jenkins-core
maven/org.jenkins-ci.main/jenkins-core
Maven
< 2.555.3
2.555.3
org.jenkins-ci.main:jenkins-core
maven/org.jenkins-ci.main/jenkins-core
Maven
≥ 2.556
< 2.568
2.568

References

NVD — CVE-2026-53437 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53437
Security Fix Commit FIX COMMIT
https://github.com/jenkinsci/jenkins/commit/b32f2f27a82ed187a34f55b05edcc4a83563d574
Security Fix Commit FIX COMMIT
https://github.com/jenkinsci/jenkins/commit/8ef52891b07eb639b38271e4bab5dab3c0f10fda
Jenkins core Security Information SECURITY
https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3711+3755
Jenkins core Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53437.json
Jenkins core Source Repository REPOSITORY
https://github.com/jenkinsci/jenkins
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2487544
Jenkins core Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-53437
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60259
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60256
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60254
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60252
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60251
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60250
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60249
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60248
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60247
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60246
access.redhat.com/errata/rhsa-2026:60... WEB
https://access.redhat.com/errata/RHSA-2026:60239

Frequently Asked Questions

What is CVE-2026-53437?
CVE-2026-53437 is a security vulnerability in Jenkins core involving Jenkins Open Redirect Through Newline/Tab Characters in Redirect URL under CWE-601: URL Redirection to Untrusted Site ('Open Redirect').
Which Jenkins core versions are affected?
Affected versions include releases prior to 2.555.3, 2.568 across affected packages: org.jenkins-ci.main:jenkins-core.
What version fixes CVE-2026-53437?
Upgrading to 2.555.3, 2.568 (or the latest patched release for your respective branch) resolves the vulnerability.
Is jenkins-core affected?
Yes, org.jenkins-ci.main:jenkins-core is affected in releases prior to 2.555.3, 2.568. Upgrade your dependency to 2.555.3, 2.568 or later.
What is the CVSS score of CVE-2026-53437?
CVE-2026-53437 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2026-53437?
CVE-2026-53437 is classified under CWE-601: URL Redirection to Untrusted Site ('Open Redirect') (The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.).
How can I check Maven dependencies for CVE-2026-53437?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.jenkins-ci.main'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-463r-5m89-4xfr",
  "modified" : "2026-08-27T15:31:26Z",
  "published" : "2026-06-10T15:31:31Z",
  "aliases" : [ "CVE-2026-53437" ],
  "summary" : "Jenkins Open Redirect Through Newline/Tab Characters in Redirect URL",
  "details" : "Jenkins 2.567 and earlier, LTS 2.555.2 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins when it contains tab or newline characters between `//`, allowing attackers to perform phishing attacks.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N"
  } ],
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    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
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      }, {
        "fixed" : "2.555.3"
      } ]
    } ]
  }, {
    "package" : {
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    },
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      "events" : [ {
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      }, {
        "fixed" : "2.568"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
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  }, {
    "type" : "WEB",
    "url" : "https://github.com/jenkinsci/jenkins/commit/b32f2f27a82ed187a34f55b05edcc4a83563d574"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jenkinsci/jenkins/commit/8ef52891b07eb639b38271e4bab5dab3c0f10fda"
  }, {
    "type" : "WEB",
    "url" : "https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3711+3755"
  }, {
    "type" : "WEB",
    "url" : "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53437.json"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jenkinsci/jenkins"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2487544"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-53437"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60259"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60256"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60254"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60252"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60251"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60250"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60249"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60248"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60247"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60246"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:60239"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-601" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-13T20:49:09Z",
    "nvd_published_at" : "2026-06-10T14:16:36Z"
  }
}