XSS in Golang Go
CVE-2026-27142
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (24.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 24.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Golang Go — versions 1.26.0
- Go Standard Library Html/template — versions 0, 1.26.0-0
Weakness classification (CWE)
References
- groups.google.com/g/golang-announce/c/EdhZqrQ98hk (Release Notes)
- go.dev/issue/77954 (Issue Tracking)
- go.dev/cl/752081 (Mailing List)
- pkg.go.dev/vuln/GO-2026-4603 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-27142?
- CVE-2026-27142 is a medium-severity vulnerability in Golang Go, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-06.
- How severe is CVE-2026-27142?
- Medium severity. CVSS v3 base score is 6.1 out of 10.