Bug 2453221 (CVE-2026-33986)

Summary: CVE-2026-33986 FreeRDP: FreeRDP: Arbitrary code execution or denial of service via H.264 codec memory allocation vulnerability
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in FreeRDP, a free implementation of the Remote Desktop Protocol. A remote attacker could exploit a memory allocation vulnerability in the H.264 codec by enticing a user to connect to a malicious server. This flaw occurs when internal buffer dimensions are incorrectly updated after a failed memory reallocation, potentially leading to a heap-based buffer overflow. Successful exploitation could result in arbitrary code execution or a denial of service (DoS), compromising the availability, integrity, and confidentiality of the affected system.
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Bug Depends On: 2453251, 2453253, 2453252    
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Description OSIDB Bzimport 2026-03-30 22:01:58 UTC 
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in yuv_ensure_buffer() in libfreerdp/codec/h264.c, h264->width and h264->height are updated before the reallocation loop. If any winpr_aligned_recalloc() call fails, the function returns FALSE but width/height are already inflated. This issue has been patched in version 3.24.2.