CVE-2026-53440: Jenkins Open Redirect Phishing Attacks Possible Vulnerability

MODERATE
Advisory Identifier: GHSA-92m7-4fpw-2wxm
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CVSS 4.3
CWE-601
Published
Advisory Summary

CVE-2026-53440 is a MODERATE (CVSS 4.3) open redirect phishing attacks possible vulnerability (CWE-601: URL Redirection to Untrusted Site ('Open Redirect')) affecting Jenkins libraries in the Maven ecosystem. The issue involves open redirect phishing attacks possible via "from" parameter in "delegate to servlet container". Remediation is available by upgrading affected packages to version 2.555.3, 2.568.

CVE-2026-53440 at a Glance

CVE Identifier CVE-2026-53440
GHSA Identifier GHSA-92m7-4fpw-2wxm
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-601: URL Redirection to Untrusted Site ('Open Redirect')
Affected Product Jenkins
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-2026-53440

To remediate this vulnerability, upgrade all affected Jenkins 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-2026-53440, 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 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, 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 does not ensure that the "from" parameter in the "Delegate to servlet container" security realm is safe to redirect to after login, allowing attackers to perform phishing attacks by redirecting users to an attacker-controlled domain.

CVE-2026-53440 Affected Jenkins 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-2026-53440 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53440
Security Fix Commit FIX COMMIT
https://github.com/jenkinsci/jenkins/commit/38071826c9a2113e1104714595262827a87b392f
Security Fix Commit FIX COMMIT
https://github.com/jenkinsci/jenkins/commit/c45e93f2d77d94ea3b0545eb5aca32b808a27586
Jenkins Source Repository REPOSITORY
https://github.com/jenkinsci/jenkins
Jenkins Security Information SECURITY
https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3721

Frequently Asked Questions

What is CVE-2026-53440?
CVE-2026-53440 is a security vulnerability in Jenkins involving Open Redirect phishing attacks possible via "from" parameter in "Delegate to servlet container" under CWE-601: URL Redirection to Untrusted Site ('Open Redirect').
Which Jenkins 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-2026-53440?
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-2026-53440?
CVE-2026-53440 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-2026-53440?
CVE-2026-53440 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-2026-53440?
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-92m7-4fpw-2wxm",
  "modified" : "2026-08-13T20:50:56Z",
  "published" : "2026-06-10T15:31:31Z",
  "aliases" : [ "CVE-2026-53440" ],
  "summary" : "Jenkins: Open Redirect phishing attacks possible via \"from\" parameter in \"Delegate to servlet container\"",
  "details" : "Jenkins 2.567 and earlier, LTS 2.555.2 and earlier does not ensure that the \"from\" parameter in the \"Delegate to servlet container\" security realm is safe to redirect to after login, allowing attackers to perform phishing attacks by redirecting users to an attacker-controlled domain.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.jenkins-ci.main:jenkins-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.555.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.jenkins-ci.main:jenkins-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.556"
      }, {
        "fixed" : "2.568"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-53440"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jenkinsci/jenkins/commit/38071826c9a2113e1104714595262827a87b392f"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jenkinsci/jenkins/commit/c45e93f2d77d94ea3b0545eb5aca32b808a27586"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jenkinsci/jenkins"
  }, {
    "type" : "WEB",
    "url" : "https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3721"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-601" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-13T20:50:56Z",
    "nvd_published_at" : "2026-06-10T14:16:36Z"
  }
}