Cross-site scripting in envoy - CVE-2026-73546
Published: August 26, 2026
Vulnerability identifier: #VU145862
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-73546
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary script in the administrator\'s browser.
The vulnerability exists due to cross-site scripting in the Envoy admin stats interface (/stats?format=html) when generating HTML output for stat names. A remote attacker can cause attacker-controlled stat names to be recorded and later rendered to execute arbitrary script in the administrator\'s browser.
Exploitation requires a component or filter that records attacker-influenced strings into stat names, and an administrator or automated tool to view the /stats?format=html endpoint in a web browser.
Affected software
envoy
Istio
Istio
How to mitigate CVE-2026-73546
Install security update from vendor's website.
envoy - addressed in versions 1.36.10, 1.37.6, 1.38.4, 1.39.1
Istio - addressed in versions 1.29.7, 1.30.4
Istio - addressed in versions 1.29.7, 1.30.4