Cross-site scripting in Go programming language - CVE-2026-39823
Published: July 31, 2026
Vulnerability identifier: #VU140610
CSH Severity: Medium
CVSS v4 BT: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green]
CVE-ID: CVE-2026-39823
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform cross-site scripting.
The vulnerability exists due to improper neutralization of input during web page generation in html/template meta content attribute escaping when rendering a template containing a URL in a tag's content attribute. A remote attacker can supply a specially crafted URL containing ASCII whitespace around the '=' character to perform cross-site scripting.
Affected software
Go programming language
How to mitigate CVE-2026-39823
Install security update from vendor's website.
Go programming language - addressed in versions 1.25.10, 1.26.3