Description

Summary

It was confirmed in a test environment that an attacker can store an HTML/JavaScript payload in a repository’s Milestone name, and when another user selects that Milestone on the New Issue page (/issues/new), a DOM-Based XSS is triggered.

Impact

Theft of information accessible in the victim’s session.
Extraction of CSRF tokens and submission of state-changing requests with the victim’s privileges.
Repository operations performed with the victim’s privileges (Issue operations, settings changes, etc.).

(The impact scope depends on the victim’s permission level.)

Remediation

A fix is available at https://github.com/gogs/gogs/releases/tag/v0.14.2

Basic information

Type: reviewed
Severity: high
Advisory on GitHub: Open advisory ↗
Repository advisory: Open repository advisory ↗
Source code: Browse source ↗
Published (advisory): 2026-03-05 20:16:20 UTC
Updated: 2026-03-05 22:28:56 UTC
GitHub reviewed: 2026-03-05 20:16:20 UTC
NVD published: 2026-03-05 19:16:04 UTC

Score	Percentile
0.03%	10.08%

CVSS Scores

Base score	Version	Severity	Vector
7.3	3.1	—	`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.

Identifiers

Type	Value
GHSA	GHSA-vgjm-2cpf-4g7c ↗
CVE	CVE-2026-26276 ↗

CWEs

CWE id	Name
CWE-79	Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Credits

odgrso (reporter)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem	Package	Vulnerable range	First patched	Vulnerable functions
go	gogs.io/gogs	<= 0.13.3	—	—

Gogs: DOM-based XSS via milestone selection