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Fencer Vulns
medium 4.3

CVE-2026-53440 json

Jenkins: Open Redirect phishing attacks possible via "from" parameter in "Delegate to servlet container"

published 2026-06-10 4 mo ago modified 2026-10-26 13 d ago also BIT-jenkins-2026-53440 , EUVD-2026-36024 , GHSA-92m7-4fpw-2wxm

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.jenkins-ci.main:jenkins-core 2.555.3, 2.568
  • bitnami jenkins 2.555.3, 2.568.0
  • Jenkins Project Jenkins 2.568

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-53440 updated cvss 4.3

jenkins: Jenkins: Phishing attacks via unsafe redirection in 'Delegate to servlet container' security realm

  • Red Hat OpenShift Developer Tools and Services jenkins
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
GitHub 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
OSV 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
maven org.jenkins-ci.main:jenkins-core
<2.555.3
>=2.556, <2.568
2.555.3
2.568
bitnami jenkins
<2.555.3
>=2.556.0, <2.568.0
2.555.3
2.568.0

Affected products

  • Jenkins Project Jenkins

Classification

Weakness
  • CWE-601 URL Redirection to Untrusted Site
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.