CVE-2026-4494 atjiu pybbs TopicApiController.java create cross site scripting
Remote attackers can inject malicious scripts via the topic creation API in pybbs, potentially leading to session hijacking or code execution.
- 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
- None listed
What is CVE-2026-4494?
CVE-2026-4494 is a medium-severity cross-site scripting vulnerability in atjiu pybbs, published on 20 Mar 2026. 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 was identified in atjiu pybbs 6.0.0. This affects the function create of the file src/main/java/co/yiiu/pybbs/controller/api/TopicApiController.java. The manipulation leads to cross site scripting. It is possible to initiate the attack remotely. The exploit is publicly available and might be used.
Which versions are affected by CVE-2026-4494?
How do I fix CVE-2026-4494?
No fix has been published for CVE-2026-4494 yet. Limit exposure of the affected software until one is available.
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-2026-4494 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4494 exists.
Sources
Also known as GHSA-9wm2-388x-gpfx.