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Fencer Vulns
medium 4.3

CVE-2026-84655 json

Jenkins 2.579 and earlier, LTS 2.568.2 and earlier does not escape map keys when serializing objects as JSON and Python through its REST AP…

published 2026-09-02 2 mo ago modified 2026-09-16 53 d ago also BIT-jenkins-2026-84655 , EUVD-2026-70121

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

Jenkins 2.579 and earlier, LTS 2.568.2 and earlier does not escape map keys when serializing objects as JSON and Python through its REST API, allowing attackers able to control map property names to inject arbitrary fields into JSON and Python API responses.

Patch / fix

  • bitnami jenkins 2.568.3, 2.580.0
  • Jenkins Project Jenkins 2.580

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-2026-84655 updated cvss 5.4

jenkins: Jenkins: Information injection via unescaped map keys in REST API

  • Red Hat OpenShift Developer Tools and Services jenkins
    affected: workaround, no fix available “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.”
  • Red Hat OpenShift Developer Tools and Services 4.12 ocp-tools-4/jenkins-rhel8 1792044326
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88152
  • Red Hat OpenShift Developer Tools and Services 4.13 ocp-tools-4/jenkins-rhel8 1792044327
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88149
  • Red Hat OpenShift Developer Tools and Services 4.14 ocp-tools-4/jenkins-rhel8 1792044382
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88151
  • Red Hat OpenShift Developer Tools and Services 4.15 ocp-tools-4/jenkins-rhel8 1792044386
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88150
  • Red Hat OpenShift Developer Tools and Services 4.16 ocp-tools-4/jenkins-rhel9 1792040287
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88156
  • Red Hat OpenShift Developer Tools and Services 4.17 ocp-tools-4/jenkins-rhel9 1792040131
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88159
  • Red Hat OpenShift Developer Tools and Services 4.18 ocp-tools-4/jenkins-rhel9 1792041514
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88153
show 5 more
  • Red Hat OpenShift Developer Tools and Services 4.19 ocp-tools-4/jenkins-rhel9 1792040733
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88158
  • Red Hat OpenShift Developer Tools and Services 4.20 ocp-tools-4/jenkins-rhel9 1792040081
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88157
  • Red Hat OpenShift Developer Tools and Services 4.21 ocp-tools-4/jenkins-rhel9 1792040096
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88155
  • Red Hat OpenShift Developer Tools and Services 4.22 ocp-tools-4/jenkins-rhel9 1792040428
    fixed: vendor fix “Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.” RHSA-2026:88154
  • Red Hat OpenShift Developer Tools and Services 4.12 ocp-tools-4/jenkins-agent-base-rhel8 1792044376 Red Hat OpenShift Developer Tools and Services 4.13 ocp-tools-4/jenkins-agent-base-rhel8 1792044361 Red Hat OpenShift Developer Tools and Services 4.14 ocp-tools-4/jenkins-agent-base-rhel8 1792044402 Red Hat OpenShift Developer Tools and Services 4.15 ocp-tools-4/jenkins-agent-base-rhel8 1792044379 Red Hat OpenShift Developer Tools and Services 4.16 ocp-tools-4/jenkins-agent-base-rhel9 1792040156 Red Hat OpenShift Developer Tools and Services 4.17 ocp-tools-4/jenkins-agent-base-rhel9 1792040149
    +5 more products
    Red Hat OpenShift Developer Tools and Services 4.18 ocp-tools-4/jenkins-agent-base-rhel9 1792041201 Red Hat OpenShift Developer Tools and Services 4.19 ocp-tools-4/jenkins-agent-base-rhel9 1792040114 Red Hat OpenShift Developer Tools and Services 4.20 ocp-tools-4/jenkins-agent-base-rhel9 1792040274 Red Hat OpenShift Developer Tools and Services 4.21 ocp-tools-4/jenkins-agent-base-rhel9 1792039948 Red Hat OpenShift Developer Tools and Services 4.22 ocp-tools-4/jenkins-agent-base-rhel9 1792040297
    not affected: vulnerable code not present

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
2 mo ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% 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:L/UI:N/S:U/C:N/I:L/A:N
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
OSV 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
bitnami jenkins
<2.568.3
>=2.569.0, <2.580.0
2.568.3
2.580.0

Affected products

  • Jenkins Project Jenkins

Classification

Weakness
  • CWE-116 Improper Encoding or Escaping of Output
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.