API response field injection via unescaped map keys
Published Sep 2, 2026 · Updated Sep 2, 2026
Output injection in Jenkins 2.579 and earlier and LTS 2.568.2 and earlier allows remote authenticated users to alter REST API responses. The JSON and Python serializers write attacker-controlled map keys without escaping them, so crafted property names become arbitrary fields in the serialized response. Exploitation requires control of a map property name exposed through the REST API; the reported consequence is response integrity loss, not code execution or data disclosure.
Summary
What happened
Output injection in Jenkins 2.579 and earlier and LTS 2.568.2 and earlier allows remote authenticated users to alter REST API responses. The JSON and Python serializers write attacker-controlled map keys without escaping them, so crafted property names become arbitrary fields in the serialized response. Exploitation requires control of a map property name exposed through the REST API; the reported consequence is response integrity loss, not code execution or data disclosure.
The record
- CVE
- CVE-2026-84655
- Published
- Sep 2, 2026
- Updated
- Sep 2, 2026
- Vendor
- Jenkins Project
- Product
- Jenkins
- Classifications
- CWE-116, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 2, 2026CVE publishedPublication date reported by the CVE source.
- Sep 2, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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