FFmpeg Out-of-Bounds Read in AV1 RTP Packetizer via rtpenc_av1.c

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

FFmpeg before commit 983dae9 contains an out-of-bounds read in the AV1 RTP packetizer (libavformat/rtpenc_av1.c). The keyframe detection loop that searches for a sequence header OBU advanced its pointer and remaining-size counter by the encoded header length plus the OBU payload size without first bounding the OBU size against the remaining data. A crafted OBU size causes the remaining-size counter to wrap to a positive value, causing the next loop iteration to dereference a pointer beyond the end of the packet buffer. A crafted AV1 input packet muxed to RTP triggers the out-of-bounds read.

Source published

19 Aug 2026 16:29:03 UTC

Source modified

27 Oct 2026 10:14:33 UTC

Observed here

27 Oct 2026 12:09:21 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 6.9 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1 · 7.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H