PatchTheCVECVE-2026-84655: Jenkins 2.579 and earlier, LTS 2.568.2 and earlier does not escape map keys when serializing objects as JSON a
CVE-2026-84655 is a medium-severity flaw (CVSS 4.3) affecting jenkins. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- No elevated risk signals yet
A fixed release or distro patch exists.
Risk facts
| CVSS score | 4.3 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 76%) |
| CISA exploited list | No |
| Weakness | CWE-116 |
| Published | 2026-09-02 |
| Last modified | 2026-09-15 |
Last updated 2026-09-15 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-84655?
jenkins: upgrade to newer than 2.579. Exact commands for each OS are on this page.
Is CVE-2026-84655 being exploited?
CVE-2026-84655 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-84655 affect?
CVE-2026-84655 affects jenkins. Severity is medium (CVSS 4.3). 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 Pyt
How urgent is CVE-2026-84655?
Priority 21/100. No elevated risk signals yet.
Software pages
Python vulnerabilities · Jenkins vulnerabilities
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