A denial of service in the subtitle decoder in FFmpeg 3.2 and 4.1 allows attackers to hog…
Priority LOW 32CWE-125Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-125 and the CVSS impact.
Summary
A denial of service in the subtitle decoder in FFmpeg 3.2 and 4.1 allows attackers to hog the CPU via a crafted video file in Matroska format, because handle_open_brace in libavcodec/htmlsubtitles.c has a complex format argument to sscanf.
Why it matters now
EPSS 0.01435 73rd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ffmpeg:ffmpeg:3.2:*:*:*:*:*:*:* | 3.2 | Vulnerable | FFmpeg |
| cpe:2.3:a:ffmpeg:ffmpeg:4.1:*:*:*:*:*:*:* | 4.1 | Vulnerable | FFmpeg |
| cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* | 18.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* | 18.10 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:* | 19.04 | Vulnerable | Canonical |
- cpe:2.3:a:ffmpeg:ffmpeg:3.2:*:*:*:*:*:*:* Versions 3.2 Vulnerable ·FFmpeg
- cpe:2.3:a:ffmpeg:ffmpeg:4.1:*:*:*:*:*:*:* Versions 4.1 Vulnerable ·FFmpeg
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* Versions 18.10 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:* Versions 19.04 Vulnerable ·Canonical
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
Not affected: 1 product
- Red Hat Enterprise Linux 5
Timeline
- 2026-10-02 Threatist record created from CVE-2019-9721
- 2026-10-03 Alias added: GHSA-hjv9-2v6w-8wp3
References
Sources
- CVE-2019-9721 · CVE Program
- CVE-2019-9721 · NVD
- FIRST EPSS
- GHSA-hjv9-2v6w-8wp3 · GitHub Advisory Database · CC BY 4.0
- CVE-2019-9721 · Red Hat security data · CC BY 4.0
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