CVE-2026-27142
html/template: URLs in meta content attribute actions are not escaped in html/template
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 7, 2026
Updated · October 30, 2026
Description
An input escaping flaw has been discovered in the golang html/template module. Actions which insert URLs into the content attribute of HTML meta tags are not escaped. This can allow XSS if the meta tag also has an http-equiv attribute with the value "refresh". A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be used to disable escaping URLs in actions in the meta content attribute which follow "url=" by setting htmlmetacontenturlescape=0.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 5.4CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')