CVE-2026-25039 The application evaluate UNC path in workspace name
Attackers can trigger NTLM hash disclosure or application hangs by using UNC paths in workspace names, affecting Parsec desktop users.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-25039?
CVE-2026-25039 is a high-severity vulnerability in Scille parsec-cloud, published on 20 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Parsec is a cloud-based application for simple and cryptographically secure file sharing. The application does not sanitize the workspace name, creating a vulnerability if that workspace name is a UNC path. When creating mountpoint in the windows filesystem to mount the workspace of an organization, the application does not sanitize the workspace name. The cause issue if the workspace name evaluate to a UNC path since it's allowed for the name to containt `\` char. If the UNC path is invalid (or the targeted resource is not available) the application become unresponsive otherwise the system will interact with the mounted UNC path allowing the attacker to retrieve to [`NTLM`] hash.
Weakness: CWE-40
Which versions are affected by CVE-2026-25039?
How do I fix CVE-2026-25039?
No fix has been published for CVE-2026-25039 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-25039 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25039 exists.
Sources
Also known as GHSA-qx56-wxpm-j4m6.