CVE-2026-27964 FacturaScripts: Reflected Cross-Site Scripting (XSS) via Cookie Manipulation
Attackers can execute arbitrary scripts in victim browsers by manipulating the fsNick cookie, bypassing logout redirects.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-27964?
CVE-2026-27964 is a low-severity cross-site scripting vulnerability in NeoRazorX facturascripts, published on 18 May 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
FacturaScripts is an open source accounting and invoicing software. Versions 2025.7 and prior contain a Reflected Cross-Site Scripting (XSS) vulnerability through the fsNick cookie parameter. The application reflects the cookie's value directly into the HTML without sanitization. The fsNick cookie is rendered into the DOM without encoding. While the server does reject the modified session and forces a logout, the HTML containing the payload reaches the browser first. This lets the script execute immediately upon load, effectively beating the redirect. This issue has been fixed in version 2025.8.
Weakness: CWE-79
Which versions are affected by CVE-2026-27964?
2 open source packages ship an affected version, including facturascripts/facturascripts.
| Package | Affected | Fixed in |
|---|---|---|
facturascripts/facturascripts Packagist | All versions to 2025.71 | None |
facturascripts/facturascripts Packagist | All versions to 2025.71 | None |
How do I fix CVE-2026-27964?
No fix has been published for CVE-2026-27964 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-2026-27964 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27964 exists.
Sources
Also known as GHSA-gq5c-rw37-g46c.