CVE-2026-78252 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in GitLab

High 8.2 Published 16 Sep 2026 Updated 16 Sep 2026

Authenticated users can trigger XSS in GitLab's Markdown renderer, potentially leading to account takeover or data modification for targeted users.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2026-78252?

CVE-2026-78252 is a high-severity cross-site scripting vulnerability in Gitlab Gitlab, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 15.3 before 19.1.8, 19.2 before 19.2.6, and 19.3 before 19.3.2 that, under certain conditions, an authenticated user could have induced a targeted user to perform unintended state-changing HTTP requests due to improper sanitization of user-controlled data in the Markdown JSON table renderer.

Weakness: CWE-79

Which versions are affected by CVE-2026-78252?

1 open source package ship an affected version, including gitlab. It affects 1 product.

Package	Affected	Fixed in
`gitlab` Bitnami	From `15.3.0`	`19.1.8, 19.2.6, 19.3.2`

Products include Gitlab Gitlab.

How do I fix CVE-2026-78252?

Upgrade gitlab to a fixed version for your release line: 19.1.8, 19.2.6 or 19.3.2.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-78252 being exploited?

There is no known exploitation of CVE-2026-78252 in the wild and no public exploit code.

All Gitlab Gitlab vulnerabilities

Sources

Also known as BIT-gitlab-2026-78252, GHSA-3xqm-9h96-4cr4, MINI-369r-mgvc-65m2, MINI-9m2r-mxmv-h3wx, MINI-fmw3-p9p2-2929.