CVE-2026-70630: medium-severity vulnerability in FFmpeg
FFmpeg 3.0 < 9.0 Uninitialized Heap Memory Read in Screenpresso Decoder
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.8epss 0.2%
FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native Screenpresso decoder (libavcodec/screenpresso.c) that allows attackers to recover sensitive memory contents by supplying a crafted SPV1 packet with a valid zlib stream that decompresses fewer bytes than the full frame requires. The screenpresso_decode_frame() function fails to validate the produced byte count before calling av_image_copy_plane() to copy the complete frame dimensions from the persistent ctx->inflated_buf buffer, causing unwritten heap memory from prior allocations or prior frames to be copied into decoded output and potentially exposing sensitive data such as userspace addresses from persistent decoding services.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
FFmpeg · FFmpegRelated CVEs — FFmpeg
In the same product, most dangerous first.
CVE-2026-8461HIGHHeap out-of-bounds write via odd slice_height in FFmpeg MagicYUV decoderEPSS 1.6%CVE-2026-64831HIGHFFmpeg 8.0 - 8.1.2 Stack Buffer Overflow in Vulkan HEVC DecoderEPSS 0.9%CVE-2026-66040HIGHFFmpeg Heap Out-of-Bounds Write via PNG/APNG eXIf EncoderEPSS 0.8%CVE-2026-64834HIGHFFmpeg 0.6.3 - 8.1.2 Infinite Loop DoS via RTP/ASF DemuxerEPSS 0.7%CVE-2026-75143CRITICALFFmpeg Heap Buffer Overflow via RIST Protocol ReaderEPSS 0.7%CVE-2026-64830HIGHFFmpeg 2.1 - 8.1.2 Heap Buffer Overflow via VobSub Subtitle DemuxerEPSS 0.6%
References
https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/705890061467ad550ecc1dad5eea07f28ccfb43ehttps://code.ffmpeg.org/FFmpeg/FFmpeg/commit/9a3202a98b2e095b54dd784c3e01a09a676fc3fahttps://code.ffmpeg.org/FFmpeg/FFmpeg/commit/c22667d0fd7916a33fd3e79685b7246fc48f1a62https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23896https://www.vulncheck.com/advisories/ffmpeg-uninitialized-heap-memory-read-in-screenpresso-decoder