CVE-2026-66040: FFmpeg through 8.1.2, fixed in commit b506faf, contains a heap out-of-bounds write vulnerability in the native

Q: How do I fix CVE-2026-66040?

ffmpeg: upgrade to newer than 8.1.2. Exact commands for each OS are on this page.

Q: Is CVE-2026-66040 being exploited?

CVE-2026-66040 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-66040 affect?

CVE-2026-66040 affects ffmpeg. Severity is high (CVSS 8.8). FFmpeg through 8.1.2, fixed in commit b506faf, contains a heap out-of-bounds write vulnerability in the native PNG and APNG encoders that allows remote attackers to corrupt heap memory by supplying a crafted PNG image with a malicious eXIf

This month

HIGH 8.8UPGRADE

CVE-2026-66040 is a high-severity flaw (CVSS 8.8) affecting ffmpeg. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

FFmpeg through 8.1.2, fixed in commit b506faf, contains a heap out-of-bounds write vulnerability in the native PNG and APNG encoders that allows remote attackers to corrupt heap memory by supplying a crafted PNG image with a malicious eXIf chunk. Attackers can craft an eXIf chunk where multiple IFD entries reference the same large value payload, causing canonical serialization to expand the output far beyond the undersized allocation estimated by

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-122
Published	2026-07-24
Last modified	2026-08-07

Publisher (CNA): VulnCheck · Vendor: ffmpeg

Last updated 2026-08-07 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-24 20:18 UTCPublished CVE record published
2026-08-07 00:35 UTCUpdated Record last modified

ffmpeg ffmpeg UPGRADE

Affected: <= 8.1.2

Fixed in: newer than 8.1.2

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 8.1.2 (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.

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-2026-66040?

ffmpeg: upgrade to newer than 8.1.2. Exact commands for each OS are on this page.

Is CVE-2026-66040 being exploited?

CVE-2026-66040 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-2026-66040 affect?

CVE-2026-66040 affects ffmpeg. Severity is high (CVSS 8.8). FFmpeg through 8.1.2, fixed in commit b506faf, contains a heap out-of-bounds write vulnerability in the native PNG and APNG encoders that allows remote attackers to corrupt heap memory by supplying a crafted PNG image with a malicious eXIf

How urgent is CVE-2026-66040?

Priority 45/100. High severity

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
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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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