CVE-2026-27142
URLs in meta content attribute actions are not escaped in html/template
Description
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.
INFO
Published Date :
March 6, 2026, 10:16 p.m.
Last Modified :
April 21, 2026, 2:30 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | ||||
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Set GODEBUG=htmlmetacontenturlescape=0 to disable URL escaping.
- Review and sanitize all URLs inserted into meta content attributes.
Public PoC/Exploit Available at Github
CVE-2026-27142 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
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-2026-27142.
| URL | Resource |
|---|---|
| https://go.dev/cl/752081 | Mailing List |
| https://go.dev/issue/77954 | Issue Tracking |
| https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk | Release Notes |
| https://pkg.go.dev/vuln/GO-2026-4603 | 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-2026-27142 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-2026-27142
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).
Terminal chat for developers: Go WebSocket server + Bubble Tea TUI client, optional E2E, reactions, DMs, channels, plugins, files, code snippets, admin UI. Backends: SQLite, PostgreSQL, or MySQL. Self-hosted.
go golang admin-panel code-snippets plugins direct-message e2e file-share messaging
Go Dockerfile Shell PowerShell HTML
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-27142 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-27142 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]
Apr. 21, 2026
Action Type Old Value New Value Added CWE CWE-79 Added CPE Configuration OR *cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* versions up to (excluding) 1.25.8 *cpe:2.3:a:golang:go:1.26.0:*:*:*:*:*:*:* Added Reference Type Go Project: https://go.dev/cl/752081 Types: Mailing List Added Reference Type Go Project: https://go.dev/issue/77954 Types: Issue Tracking Added Reference Type Go Project: https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk Types: Release Notes Added Reference Type Go Project: https://pkg.go.dev/vuln/GO-2026-4603 Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Mar. 16, 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 Removed CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Mar. 10, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H -
New CVE Received by [email protected]
Mar. 06, 2026
Action Type Old Value New Value Added Description 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. Added Reference https://go.dev/cl/752081 Added Reference https://go.dev/issue/77954 Added Reference https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk Added Reference https://pkg.go.dev/vuln/GO-2026-4603