What is CVE-2026-42502?

CVE-2026-42502 is a medium-severity vulnerability in Golang Net, classified under Improper Restriction of Rendered UI Layers or Frames (Clickjacking). CVSS score: 6.1/10. Published 2026-05-22.

How severe is CVE-2026-42502?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Vulnerability in Golang Net

CVE-2026-42502

Parsing arbitrary HTML which is then rendered using Render can result in an unexpected HTML tree. This can be leveraged to execute XSS attacks in applications that attempt to sanitize input HTML before rendering.

Published 2026-05-22 · last modified 2026-07-23.

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: 0.002 (12.0th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Golang Net
Golang.org/x/net Golang.org/x/net/html — versions 0

Weakness classification (CWE)

CWE-1021 — Improper Restriction of Rendered UI Layers or Frames (Clickjacking)

References

go.dev/issue/79572 (Issue Tracking)
groups.google.com/g/golang-announce/c/iI-mYSI0lu8 (Mailing List)
go.dev/cl/781701 (Issue Tracking)
pkg.go.dev/vuln/GO-2026-5027 (Vendor Advisory)

Frequently asked questions

What is CVE-2026-42502?: CVE-2026-42502 is a medium-severity vulnerability in Golang Net, classified under Improper Restriction of Rendered UI Layers or Frames (Clickjacking). CVSS score: 6.1/10. Published 2026-05-22.
How severe is CVE-2026-42502?: Medium severity. CVSS v3 base score is 6.1 out of 10.