Vulnerability · Published Aug 1, 2026 · Assigned by VulnCheck

CVE-2026-67305FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr

Critical 9.4

In plain English

A critical-severity heap buffer overflow in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 56% of all known vulnerabilities).

Severity (CVSS 4.0)9.4Critical

Exploit odds (30 days)0.8%top 44.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

FreeRDP Windows client before 3.29.0 contains a heap buffer overflow vulnerability in the clipboard virtual channel when processing CLIPRDR_FILE_CONTENTS_RESPONSE PDUs without validating the server-provided size against the destination buffer. A malicious RDP server can send a response with a data payload significantly larger than requested, causing arbitrary heap memory corruption that may enable remote code execution when a user performs a paste operation.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Ubuntu:22.04:LTS	freerdp2	no fix listed	UBUNTU-CVE-2026-67305
Ubuntu:24.04:LTS	freerdp3	no fix listed	UBUNTU-CVE-2026-67305
Ubuntu:26.04:LTS	freerdp3	no fix listed	UBUNTU-CVE-2026-67305

Affected products (as reported)

Vendor	Product	Versions
FreeRDP	FreeRDP	0 – before 3.29.0

Weakness: CWE-122 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

References

GitHub Security Advisory (GHSA-cj9v-h4hq-29jr) vendor-advisory
VulnCheck Advisory: FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr third-party-advisory