What’s Vulnerable › Vulnerabilities

CVE-2026-55566: Yamcs: DOM XSS in Extension Routing

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-28 · updated 2026-09-08
• Weakness: CWE-79

Description

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs processes attacker-controlled data from the /ext URL route in yamcs-web/src/main/webapp/projects/webapp/src/app/core/routes/extension.matcher.ts, extension.component.ts, and app.component.ts without checking registered plugin IDs before DOM rendering through innerHTML. A crafted URL can execute JavaScript when opened by a user. The script can read data available to the Yamcs web application and perform actions in the user context. This issue is fixed in versions 5.12.8 and 5.13.2.

Affected products

• yamcs: before 5.12.8; from 5.13.0, < 5.13.2

References

• https://github.com/yamcs/yamcs/commit/8e18e279d8ce761c21f4f67bbd06a1bff804d297
• https://github.com/yamcs/yamcs/commit/ecf34a4e2ccbe085e6ceff0253595b24d5ecb4aa
• https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.8
• https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.2
• https://github.com/yamcs/yamcs/security/advisories/GHSA-9272-wg2r-7xmx
• https://github.com/yamcs/yamcs/security/advisories/GHSA-9272-wg2r-7xmx

Get alerted when CVE-2026-55566 or the next vulnerability affects your stack