CVE-2026-27099
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Description
A flaw was found in Jenkins. This vulnerability, identified as a stored cross-site scripting (XSS) issue, occurs because Jenkins does not properly escape the user-provided description for the "Mark temporarily offline" cause. An attacker with Agent/Configure or Agent/Disconnect permissions can exploit this to inject malicious scripts, leading to potential information disclosure or unauthorized actions within the user's browser.
Statement
This vulnerability in Jenkins allows authenticated attackers with Agent/Configure or Agent/Disconnect permissions to inject malicious scripts into the "Mark temporarily offline" cause description. This stored cross-site scripting (XSS) flaw can lead to information disclosure or unauthorized actions within a user's browser when viewing the affected description. Red Hat OpenShift Developer Tools & Services are affected.
Additional Information
- This content is not included.Bugzilla 2440638: org.jenkins-ci.main/jenkins-core: Jenkins: Stored Cross-site Scripting (XSS) via unescaped user-provided offline cause description
- Content from cwe.mitre.org is not included.CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- FAQ: Frequently asked questions about CVE-2026-27099
- Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.
External References
Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2026-27099
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2026-27099
Affected Packages and Issued Red Hat Security Errata
| Products / Services | Components | State | Errata |
|---|---|---|---|
| OpenShift Developer Tools and Services | jenkins | Fix deferred | |
| OpenShift Developer Tools and Services 4.12 | ocp-tools-4/jenkins-rhel8 | Fixed | RHSA-2026:10209 |
| OpenShift Developer Tools and Services 4.13 | ocp-tools-4/jenkins-rhel8 | Fixed | RHSA-2026:10201 |
| OpenShift Developer Tools and Services 4.14 | ocp-tools-4/jenkins-rhel8 | Fixed | RHSA-2026:10211 |
| OpenShift Developer Tools and Services 4.15 | ocp-tools-4/jenkins-rhel8 | Fixed | RHSA-2026:10204 |
| OpenShift Developer Tools and Services 4.16 | ocp-tools-4/jenkins-rhel9 | Fixed | RHSA-2026:10214 |
| OpenShift Developer Tools and Services 4.17 | ocp-tools-4/jenkins-rhel9 | Fixed | RHSA-2026:10213 |
| OpenShift Developer Tools and Services 4.18 | ocp-tools-4/jenkins-rhel9 | Fixed | RHSA-2026:10215 |
| OpenShift Developer Tools and Services 4.19 | ocp-tools-4/jenkins-rhel9 | Fixed | RHSA-2026:10206 |
| OpenShift Developer Tools and Services 4.2 | ocp-tools-4/jenkins-rhel9 | Fixed | RHSA-2026:10205 |
| OpenShift Developer Tools and Services 4.21 | ocp-tools-4/jenkins-rhel9 | Fixed | RHSA-2026:10199 |
Common Vulnerability Scoring System (CVSS) Score Details
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 Authorities (CNA) source for its products and services (see Red Hat classifications ).
| CVSS v3 Score Breakdown | Red Hat | NVD |
|---|---|---|
| CVSS v3 Base Score | 4.6 | |
| Attack Vector | Network | |
| Attack Complexity | Low | |
| Privileges Required | Low | |
| User Interaction | Required | |
| Scope | Unchanged | |
| Confidentiality Impact | Low | |
| Integrity Impact | Low | |
| Availability Impact | None |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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