Client crash via unchecked H.264 rectangle coordinates
Published Mar 13, 2026 · Updated Mar 13, 2026
Heap buffer overflow in FreeRDP before 3.24.0 allows remote attackers operating an RDP server to crash a connecting client. The clamp function in libfreerdp/codec/yuv.c checks vertical regionRects bounds but leaves left and right unchecked, so avc420_yuv_to_rgb derives out-of-range pointers and writes beyond the surface buffer. Exploitation requires a client connection that negotiates AVC420 or AVC444 graphics; heap corruption follows, but code execution is not established.
Summary
What happened
Heap buffer overflow in FreeRDP before 3.24.0 allows remote attackers operating an RDP server to crash a connecting client. The clamp function in libfreerdp/codec/yuv.c checks vertical regionRects bounds but leaves left and right unchecked, so avc420_yuv_to_rgb derives out-of-range pointers and writes beyond the surface buffer. Exploitation requires a client connection that negotiates AVC420 or AVC444 graphics; heap corruption follows, but code execution is not established.
The record
- CVE
- CVE-2026-29774
- Published
- Mar 13, 2026
- Updated
- Mar 13, 2026
- Vendor
- FreeRDP
- Product
- FreeRDP
- Classifications
- CWE-787, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 13, 2026CVE publishedPublication date reported by the CVE source.
- Mar 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.24.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Deterministic malicious RDP server PoCproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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