CVE-2026-34417 OSCAL-GUI Reflected XSS via project parameter in oscal-forms.php
Unauthenticated attackers can execute arbitrary JavaScript in victims' browsers via reflected XSS in the project parameter of OSCAL-GUI.
- 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
- None listed
What is CVE-2026-34417?
CVE-2026-34417 is a medium-severity cross-site scripting vulnerability in brian-ruf OSCAL-GUI, published on 9 Jun 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
OSCAL-GUI contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in a victim's browser by injecting malicious content through the project request parameter in oscal-forms.php. The parameter value is URL-decoded and assigned to the project_id variable without sanitization in oscal-functions.php, and when the supplied project ID is not found, the unsanitized value is concatenated into an error message via the Messages() function and reflected into the HTML response body without encoding.
Weakness: CWE-79
Which versions are affected by CVE-2026-34417?
How do I fix CVE-2026-34417?
No fix has been published for CVE-2026-34417 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-2026-34417 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34417 exists.
Sources
Also known as GHSA-79q4-fp7f-qmxh.