# CVE-2026-117621: Jenkins workspace browser XSS in agent URL computation

Source: https://junglewise.ai/threats/cve-2026-117621-jenkins-2-587-and-earlier-lts-2-580-1-and-earlier-computes-on  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-28. Updated: 2026-10-28  
License: CC BY 4.0 with a link back

CVE-2026-117621 · Severity: info · Published 2026-10-28

Jenkins is an automation server used to orchestrate software builds and deployments. The workspace browser feature computes URLs for files and directories by running code on build agents, but improperly escapes the results, allowing attackers who control an agent to inject malicious scripts that execute in an administrator's browser when viewing the workspace.

Technologies: [Jenkins](https://junglewise.ai/threats/technologies/jenkins). Vendors: [Jenkins](https://junglewise.ai/threats/vendors/jenkins).

## Quick answers

**Is CVE-2026-117621 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-117621 being exploited in the wild.

**How severe is CVE-2026-117621?** Informational severity, published 28 October 2026.

**Which products and versions are affected?** Jenkins 2.587 and earlier, LTS 2.580.1 and earlier.

**Is there a fix for CVE-2026-117621?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-117621 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-117621?** Check whether you run Jenkins at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

Jenkins 2.587 and earlier, LTS 2.580.1 and earlier compute file and directory URLs in the workspace browser on the agent side without proper output encoding; an attacker with agent process control can inject JavaScript into these URLs, resulting in stored XSS when a user with appropriate permissions views the workspace. The vulnerability requires the attacker to already control an agent process. No mitigation or workaround is mentioned in the advisory.

## Affected products

- Jenkins Jenkins 2.587 and earlier, LTS 2.580.1 and earlier

## References

- [https://www.jenkins.io/security/advisory/2026-10-28/](https://www.jenkins.io/security/advisory/2026-10-28/)

## Related threats

- [Jenkins path traversal in file browser workspace disclosure](https://junglewise.ai/threats/cve-2026-117626-jenkins-2-587-and-earlier-lts-2-580-1-and-earlier-improperly)
- [Jenkins missing HTTP proxy permission check](https://junglewise.ai/threats/cve-2026-117625-a-missing-permission-check-in-jenkins-2-587-and-earlier-lts-2)
- [Jenkins deserialization filter bypass in XStream resolves-to attribute](https://junglewise.ai/threats/cve-2026-117624-jenkins-2-587-and-earlier-lts-2-580-1-and-earlier-does-not)
- [Jenkins stored cross-site scripting in breadcrumb menu tooltips](https://junglewise.ai/threats/cve-2026-117623-jenkins-2-587-and-earlier-lts-2-580-1-and-earlier-does-not)
- [Jenkins agent XSS via Stapler HttpResponse exceptions](https://junglewise.ai/threats/cve-2026-117622-jenkins-2-587-and-earlier-lts-2-580-1-and-earlier-allows-agents)