CVE-2025-2123 GeSHi CSS cssgen.php get_var cross site scripting
Attackers can inject malicious scripts via CSS generation parameters in GeSHi, potentially executing code in user browsers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-2123?
CVE-2025-2123 is a medium-severity cross-site scripting vulnerability in GeSHi, published on 9 Mar 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
A vulnerability, which was classified as problematic, has been found in GeSHi up to 1.0.9.1. Affected by this issue is the function get_var of the file /contrib/cssgen.php of the component CSS Handler. The manipulation of the argument default-styles/keywords-1/keywords-2/keywords-3/keywords-4/comments leads to cross site scripting. The attack may be launched remotely. The exploit has been disclosed to the public and may be used.
Which versions are affected by CVE-2025-2123?
2 open source packages ship an affected version, including geshi/geshi. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
geshi/geshi Packagist | All versions to 1.0.9.1 | None |
geshi/geshi Packagist | All versions to 1.0.9.1 | None |
Products include Qbnz Geshi.
How do I fix CVE-2025-2123?
Upgrade to a fixed version.
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-2025-2123 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-2123 exists.
Other vulnerabilities in GeSHi
Sources
Also known as DEBIAN-CVE-2025-2123, GHSA-pr6q-g5gv-qgr7, UBUNTU-CVE-2025-2123.