CVE-2026-84655
Description
A flaw was found in Jenkins. When serializing objects as JSON and Python through its REST API, Jenkins does not properly escape map keys. This allows an attacker who can control map property names to inject arbitrary fields into JSON and Python API responses, potentially leading to information disclosure or manipulation of data.
Statement
A flaw was found in Jenkins. Information injection is possible via unescaped map keys in the REST API, allowing attackers to inject arbitrary fields into API responses. This issue affects Jenkins versions up to 2.579 (weekly) and up to 2.568.2 (LTS).
Mitigation
Update to Jenkins 2.580 (weekly) or Jenkins LTS 2.568.3 or later.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.4 | N/A | 4.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Modify Application Data; Execute Unauthorized Code or Commands
An attacker could modify the structure of the message or data being sent to the downstream component. When the wrong encoding is used - even if closely related - the downstream component could decode the data incorrectly and misinterpret the output. This can have security consequences when the provided boundaries between control and data are inadvertently broken, because the resulting data could introduce control characters or special elements that were not sent by the product. The resulting data could then be used to bypass protection mechanisms such as input validation, and enable injection attacks.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
