What is CVE-2026-84655?

CVE-2026-84655 is a medium-severity vulnerability, classified under Improper Encoding or Escaping of Output. CVSS score: 4.3/10. Published 2026-09-02.

How severe is CVE-2026-84655?

Medium severity. CVSS v3 base score is 4.3 out of 10.

CVE-2026-84655

CVE-2026-84655

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.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

Weakness classification (CWE)

CWE-116 — Improper Encoding or Escaping of Output

References

jenkinsci-cert@googlegroups.com (vendor-advisory)

Frequently asked questions

What is CVE-2026-84655?: CVE-2026-84655 is a medium-severity vulnerability, classified under Improper Encoding or Escaping of Output. CVSS score: 4.3/10. Published 2026-09-02.
How severe is CVE-2026-84655?: Medium severity. CVSS v3 base score is 4.3 out of 10.