CVE-2026-66038
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk16th percentile - higher than 16% of all known CVEs
Summary
FFmpeg through 8.1.2 contains an information disclosure vulnerability in the LCL/ZLIB video decoder that allows attackers to expose uninitialized heap memory by supplying a valid zlib stream that inflates to fewer bytes than the expected frame size. The zlib_decomp() function in lcldec.c treats short decompression as non-fatal and continues to the RGB24 conversion path, copying uninitialized heap contents into the attacker-observable AVFrame output, potentially defeating ASLR in long-lived media processing services.
Risk Assessment
Exposure of uninitialized heap memory may allow an attacker to read sensitive data or bypass security mechanisms like ASLR, increasing the risk of further attacks on the system.
Recommendation
Update FFmpeg to a version containing commit 8670835, which fixes this vulnerability, and consider restricting access to decoding untrusted video streams.
Other vulnerabilities in FFmpeg
See all- CVE-2017-15672High
The read_header function in libavcodec/ffv1dec.c in FFmpeg 2.4 and 3.3.4 and possibly earlier allows remote attackers to have unspecified impact via a crafted MP4 file, which triggers an out-of-bounds read.
- CVE-2017-14767High
The sdp_parse_fmtp_config_h264 function in libavformat/rtpdec_h264.c in FFmpeg before version 3.3.4 mishandles empty sprop-parameter-sets values, allowing remote attackers to cause a denial of service (heap buffer overflow) or possibly have unspecified other impact via a crafted sdp file.
- CVE-2017-14225High
The av_color_primaries_name function in libavutil/pixdesc.c in FFmpeg 3.3.3 may return a NULL pointer depending on a value contained in a file, leading to a NULL pointer dereference in the avcodec_string function in libavcodec/utils.c.
- CVE-2012-2805High
Unspecified vulnerability in FFMPEG 0.10 allows remote attackers to cause a denial of service.
- CVE-2017-11719High
The dnxhd_decode_header function in libavcodec/dnxhddec.c in FFmpeg versions 3.0 through 3.3.2 allows remote attackers to cause a denial of service (out-of-array access) or possibly have unspecified other impact via a crafted DNxHD file.
- CVE-2017-11665High
The ff_amf_get_field_value function in libavformat/rtmppkt.c in FFmpeg 3.3.2 allows remote RTMP servers to cause a denial of service via a crafted stream, leading to segmentation violation and application crash.
- CVE-2017-9996High
The cdxl_decode_frame function in libavcodec/cdxl.c in FFmpeg before versions 2.8.12, 3.0.8, 3.1.8, 3.2.5, and 3.3.1 does not exclude the CHUNKY format, allowing remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted file.
- CVE-2017-9995High
In libavcodec/scpr.c in FFmpeg version 3.3 and earlier, before version 3.3.1, height and width data is not properly validated, allowing remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted file.
- CVE-2017-9993High
FFmpeg versions before 2.8.12, 3.0.x and 3.1.x before 3.1.9, 3.2.x before 3.2.6, and 3.3.x before 3.3.2 do not properly restrict HTTP Live Streaming filename extensions and demuxer names, allowing attackers to read arbitrary files via crafted playlist data.
- CVE-2017-9992High
A heap-based buffer overflow in the decode_dds1 function in libavcodec/dfa.c in FFmpeg before 2.8.12, 3.0.x before 3.0.8, 3.1.x before 3.1.8, 3.2.x before 3.2.5, and 3.3.x before 3.3.1 allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted file.
Original NVD description (English source)
FFmpeg through 8.1.2, fixed in commit 8670835, contains an information disclosure vulnerability in the LCL/ZLIB video decoder that allows attackers to expose uninitialized heap memory by supplying a valid zlib stream that inflates to fewer bytes than the expected frame size. The zlib_decomp() function in lcldec.c treats short decompression as non-fatal and continues to the RGB24 conversion path, which copies a full frame's worth of rows from the allocation buffer using original frame dimensions, causing uninitialized heap contents including pointer-derived allocator bytes to be copied into the attacker-observable AVFrame output and potentially defeating ASLR in long-lived media processing services.