XSS in Brian-Ruf Oscal-Gui
CVE-2026-34417
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (19.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Brian-Ruf Oscal-Gui — versions 0
Weakness classification (CWE)
References
- gist.github.com/cyberinforepo/5a8d369a005826b6b42bfeed9607c2dd (technical-description, exploit)
- www.vulncheck.com/advisories/oscal-gui-reflected-xss-via-project-parameter-in-o… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-34417?
- CVE-2026-34417 is a medium-severity vulnerability in Brian-Ruf Oscal-Gui, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-06-09.
- How severe is CVE-2026-34417?
- Medium severity. CVSS v3 base score is 6.1 out of 10.