CVE-2026-25039 (CVSS 8.8)

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.

Is your site exposed to CVE-2026-25039?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0034

Probability of exploitation

0.27%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-40 CWE-40

References

Other References

https://github.com/Scille/parsec-cloud/security/advisories/GHSA-qx56-wxpm-j4m6 https://github.com/Scille/parsec-cloud/security/advisories/GHSA-qx56-wxpm-j4m6

Frequently Asked Questions

What is CVE-2026-25039? +

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. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-25039? +

CVE-2026-25039 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0034, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-25039? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-32103 5.0

CrushFTP 9.x and 10.x through 10.8.4 and 11.x through 11.3.1 allows directory traversal via the /WebInterface/function/ URI to read files …

CVE-2023-29446 4.7

An improper input validation vulnerability has been discovered that could allow an adversary to inject a UNC path via a …

CVE-2026-25039