CVE-2026-55191
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients that negotiate RDPGFX AVC444 with an H.264 decoder backend calculate the intermediate YUV444 allocation size in libfreerdp/codec/h264.c with 32-bit multiplication in avc444_ensure_buffer. A malicious RDP server can supply surface dimensions for which piDstStride multiplied by padDstHeight wraps to a small nonzero value, causing winpr_aligned_recalloc to allocate an undersized buffer before YUV420CombineToYUV444 writes using the actual stride and rectangle dimensions. This can cause a client crash and may permit code execution through attacker-influenced heap corruption. This issue is fixed in version 3.27.0.
Is your site exposed to CVE-2026-55191?
Run a free security scan — no signup, results in seconds.
EPSS — Exploit Prediction
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)
References
Other References
Frequently Asked Questions
What is CVE-2026-55191? +
How do I check if I'm vulnerable to CVE-2026-55191? +
Related Vulnerabilities
vifm is vulnerable to a heap buffer overflow during the history merge process when saving the state file (vifminfo.json). This …
A heap buffer overflow vulnerability exists in the Jansi JNI "ioctl()" wrapper due to a lack of size verification for …
A type confusion vulnerability in Qt SVG allows an attacker to cause an application crash via a crafted SVG image. …
Heap-based Buffer Overflow vulnerability in RTI Connext Professional (Core Libraries) allows Overflow Variables and Tags.This issue affects Connext Professional: from …
Heap-based Buffer Overflow vulnerability in iniparser_dumpsection_ini() in iniparser allows attacker to read out of bound memory
There is a Heap-based Buffer Overflow vulnerability in QTextMarkdownImporter. This requires an incorrectly formatted markdown file to be passed to …