CVE-2026-70629: FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability

Routine

MEDIUM 5.5UPGRADE

CVE-2026-70629 is a medium-severity flaw (CVSS 5.5) affecting ffmpeg. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native RSCC decoder (libavcodec/rscc.c) that allows attackers to disclose heap memory contents by supplying a crafted video file with a compressed tile that decompresses fewer bytes than the declared tile geometry requires. When rscc_decode_frame() calls av_image_copy_plane() without validating the decompressed byte count against

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 93%)
CISA exploited list	No
Weakness	CWE-908
Published	2026-08-06
Last modified	2026-09-01

Publisher (CNA): VulnCheck · Vendor: ffmpeg

Last updated 2026-09-01 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-06 22:18 UTCPublished CVE record published
2026-09-01 15:36 UTCUpdated Record last modified

ffmpeg ffmpeg UPGRADE

Affected: >= 3.0 and < 9

Fixed in: 9

Safe to downgrade to: a release before 3.0

1. Check installed version

apt-cache policy ffmpeg || rpm -q ffmpeg || ffmpeg --version

2. UPGRADE to 9 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ffmpeg

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ffmpeg

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.0 (Debian / Ubuntu)

apt-cache madison ffmpeg sudo apt install ffmpeg=<VERSION_BEFORE_3.0> sudo apt-mark hold ffmpeg

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list ffmpeg sudo dnf downgrade ffmpeg-<VERSION_BEFORE_3.0> sudo dnf versionlock add ffmpeg

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-70629?

ffmpeg: upgrade to 9. Exact commands for each OS are on this page.

Is CVE-2026-70629 being exploited?

CVE-2026-70629 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-70629 affect?

CVE-2026-70629 affects ffmpeg. Severity is medium (CVSS 5.5). FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native RSCC decoder (libavcodec/rscc.c) that allows attackers to disclose heap memory contents by supplying a crafted vide

How urgent is CVE-2026-70629?

Priority 21/100. No elevated risk signals yet.

Software pages

FFmpeg vulnerabilities

Related CVEs

CVE-2026-64831 HIGH 8.8 UPGRADE FFmpeg versions 8.0 through 8.1.2 contains a stack buffer overflow vulnerability in the Vulkan HEVC hardware d
CVE-2026-64834 HIGH 7.5 UPGRADE FFmpeg versions 0.6.3 through 8.1.2 contain an infinite loop vulnerability in the RTP/ASF demuxer within libav
CVE-2026-64830 HIGH 8.8 UPGRADE FFmpeg versions 2.1 through 8.1.2 contains a heap buffer overflow vulnerability in the VobSub subtitle demuxer
CVE-2026-64835 HIGH 8.8 UPGRADE FFmpeg versions 4.4 through 8.1.2 contain an out-of-bounds memory access vulnerability in the ADX audio decode
CVE-2026-64832 HIGH 8.8 UPGRADE FFmpeg versions 4.4 through 8.1.2 contain a double-free vulnerability in the NVIDIA NVDEC hardware decoder wit

References

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