CVE-2026-40254

FreeRDP: contains_dotdot() off-by-one allows drive channel path traversal via terminal ..

CVSS 4.2 MEDIUMEPSS 0.2%CWE-193

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 4.2EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

24 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

FreeRDP is a free implementation of the Remote Desktop Protocol. Versions prior to 3.25.0 have an off-by-one in the path traversal filter in `channels/drive/client/drive_file.c`. The `contains_dotdot()` function catches `../` and `..\` mid-path but misses `..` when it's the last component with no trailing separator. A rogue RDP server can read, list, or write files one directory above the client's shared folder through RDPDR requests. This requires the victim to connect with drive redirection enabled. Version 3.25.0 patches the issue.

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

Affected products

FreeRDP · FreeRDP

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References

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3xpj-m4hx-8vmx