CVE-2026-50591 Cross-site scripting in Znuny
Attackers can inject malicious scripts via stored user preferences in Znuny, 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
- Available
What is CVE-2026-50591?
CVE-2026-50591 is a medium-severity cross-site scripting vulnerability in Znuny, published on 5 Jun 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
In Znuny LTS before 6.5.21 and Znuny before 7.3.3, XSS can occur via stored user preferences.
Weakness: CWE-79
Which versions are affected by CVE-2026-50591?
How do I fix CVE-2026-50591?
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-2026-50591 being exploited?
There is no known exploitation of CVE-2026-50591 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-50591, GHSA-qfgf-x7qr-jq6q, UBUNTU-CVE-2026-50591.