CVE-2026-42502
Invoking incorrect handling of HTML elements in foreign content in golang.org/x/net/html
Description
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.
INFO
Published Date :
May 22, 2026, 4:16 p.m.
Last Modified :
May 29, 2026, 7:09 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Sanitize all HTML input before rendering.
- Implement a robust HTML sanitization library.
- Update rendering components to newer versions.
- Review security configurations for rendering.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42502.
| URL | Resource |
|---|---|
| https://go.dev/cl/781701 | Issue Tracking |
| https://go.dev/issue/79572 | Issue Tracking |
| https://groups.google.com/g/golang-announce/c/iI-mYSI0lu8 | Mailing List |
| https://pkg.go.dev/vuln/GO-2026-5027 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42502 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42502
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42502 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42502 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 29, 2026
Action Type Old Value New Value Added CWE CWE-1021 Added CPE Configuration OR *cpe:2.3:a:golang:net:*:*:*:*:*:go:*:* versions up to (excluding) 0.55.0 Added Reference Type Go Project: https://go.dev/cl/781701 Types: Issue Tracking Added Reference Type Go Project: https://go.dev/issue/79572 Types: Issue Tracking Added Reference Type Go Project: https://groups.google.com/g/golang-announce/c/iI-mYSI0lu8 Types: Mailing List Added Reference Type Go Project: https://pkg.go.dev/vuln/GO-2026-5027 Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 22, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N -
New CVE Received by [email protected]
May. 22, 2026
Action Type Old Value New Value Added Description 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. Added Reference https://go.dev/cl/781701 Added Reference https://go.dev/issue/79572 Added Reference https://groups.google.com/g/golang-announce/c/iI-mYSI0lu8 Added Reference https://pkg.go.dev/vuln/GO-2026-5027