CVE-2026-66041: ffmpeg Out-of-bounds Write
Vulnerability summary
CVE-2026-66041 is a high (CVSS 8.8) Out-of-bounds Write vulnerability in ffmpeg. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 40.6% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 5 · Related 5Timeline
- 24-07-2026PublishedVulnerability first disclosed.
- 29-07-2026Last modifiedVulnerability information updated.
Description
FFmpeg 7.0 through 8.1.2, fixed in commit 4da9812, contains a heap out-of-bounds write vulnerability in the vf_quirc filter that allows an attacker to corrupt heap memory by supplying a crafted PGS/SUP subtitle file with mismatched frame dimensions. Attackers can provide a subtitle file whose second presentation has larger dimensions than its first, causing av_image_copy_plane() to copy data exceeding the initial allocation size into the undersized libquirc grayscale image buffer, resulting in heap corruption and process crash with potential for code execution.
CVSS metrics
9 scores · 6 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.7HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- OSV · WolfiEcosystem advisory · calculated7.7HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated7.7HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- NVDNIST7.7HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
EPSS trend
Probability
0.49%
Chance of exploitation in the next 30 days
Percentile
41%
Versus all other CVEs
30-day change
-0.05 pp
From 0.54% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (code.ffmpeg.org)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Chainguard10 products
- eco-python-ffmpeg-7-minimalAll versions (No fix recorded)
- eco-python-ffmpeg-7-minimal-devAll versions (No fix recorded)
- eco-python-ffmpeg-7-minimal-staticAll versions (No fix recorded)
- eco-python-ffmpeg-8-minimal< 8.1.3-r0
- eco-python-ffmpeg-8-minimal-dev< 8.1.3-r0
Wolfi4 products
- ffmpeg-7All versions (No fix recorded)
- ffmpeg-7.1All versions (No fix recorded)
- ffmpeg-8.0All versions (No fix recorded)
- ffmpeg-8.1All versions (No fix recorded)
Debian1 product
- ffmpegAll versions (No fix recorded) | < 7:9.0.2-1
Ffmpeg1 product
- ffmpeg≥ 7.0, ≤ 8.1.2
Ubuntu1 product
- ffmpegAll versions (No fix recorded)
5 vendors · 17 products
References
9 links- www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-via-vf-quirc-filterThird Party AdvisoryREPORTAdvisory
