Description

FFmpeg versions 4.4 through 8.1.2 contain a double-free vulnerability in the NVIDIA NVDEC hardware decoder within libavcodec/nvdec.c that allows attackers to trigger memory corruption by supplying a crafted video file. When no decoder surfaces remain, the ff_nvdec_start_frame_sep_ref error path frees memory via nvdec_fdd_priv_free while the calling layer subsequently frees the same frame description data, resulting in a double-free of the underlying decoder context in any FFmpeg-based application using NVDEC hardware-accelerated decoding.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-07-22T18:17:05.483Z",
  "pubdate": "2026-07-22T18:17:05.483Z",
  "executiveSummary": "A critical double-free vulnerability exists in the NVIDIA NVDEC hardware decoder component of FFmpeg versions 4.4 through 8.1.2. The flaw resides within libavcodec/nvdec.c and can be triggered when an attacker supplies a specifically crafted malicious video file to an application utilizing FFmpeg for hardware-accelerated video decoding. Successful exploitation of this vulnerability leads to heap memory corruption, which can potentially result in arbitrary code execution or cause a denial of service via application crashes. The attack requires no authentication or special privileges on the target system, but it relies on user interaction or automated ingestion of the malicious media payload by an vulnerable FFmpeg-based application. Given the ubiquity of FFmpeg in media processing pipelines, web browsers, and media players, this vulnerability presents significant risk implications for systems processing untrusted video streams using hardware acceleration.",
  "technicalDetails": "The vulnerability is a classic double-free memory corruption flaw located in the NVIDIA NVDEC hardware decoder implementation within the libavcodec/nvdec.c source file of FFmpeg. Specifically, the error path handled by the ff_nvdec_start_frame_sep_ref function is susceptible to improper resource management during frame initialization. When the decoder encounters a state where no decoder surfaces remain available, the error handling path explicitly invokes nvdec_fdd_priv_free to deallocate the frame description data associated with the context. However, the calling execution layer is not properly synchronized or informed of this internal deallocation, leading it to subsequently attempt a second deallocation of the exact same frame description data block. This redundant release of identical heap memory pointers constitutes a double-free condition within the underlying decoder context. The attack flow begins when an attacker crafts a malicious video file designed to exhaust available decoder surfaces or trigger specific boundary conditions during parsing and decoding initialization within the NVDEC pipeline. When an FFmpeg-based application processes this crafted video file, the parsing of the stream forces the decoder into the vulnerable error path of ff_nvdec_start_frame_sep_ref. The double-free execution subsequently corrupts the internal heap management metadata structures of the allocator. Depending on heap layout and exploitation sophistication, an attacker may leverage this memory corruption to manipulate adjacent heap objects, achieve arbitrary read/write primitives, or execute arbitrary code within the security context of the process running the vulnerable FFmpeg library. The affected component is strictly the NVIDIA NVDEC hardware acceleration module, impacting all FFmpeg versions ranging from 4.4 up to and including 8.1.2. Exploitation does not require network exposure, authentication, or elevated privileges, provided the target application processes the crafted media file."
}