CVE-2026-55192 (GCVE-0-2026-55192)
Vulnerability from cvelistv5 – Published: 2026-08-19 17:51 – Updated: 2026-08-25 03:36
VLAI
EPSS
VEX
Title
FreeRDP: Out-of-bounds read in H.264 YUV-to-RGB conversion due to decoder/surface dimension mismatch
Summary
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP H.264 decoder backends can return YUV planes sized from the bitstream without comparing the decoded width and height to the RDPGFX surface dimensions used to validate region rectangles. A malicious RDP server can provide an AVC420 or AVC444 bitstream whose decoded frame is smaller than the negotiated surface, causing yuv420_context_decode and the YUV-to-RGB conversion paths to read beyond the decoder-owned planes in libfreerdp/codec/h264.c and the selected H.264 backend. This can disclose client memory or crash the client. This issue is fixed in version 3.27.0.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-25 03:35 UTC
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/FreeRDP/FreeRDP/security/advis… | x_refsource_CONFIRM |
| https://github.com/FreeRDP/FreeRDP/pull/12873 | x_refsource_MISC |
| https://github.com/FreeRDP/FreeRDP/commit/0cd45b7… | x_refsource_MISC |
| https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0 | x_refsource_MISC |
Impacted products
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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