CVE-2026-75141
CVE-2026-75141 — FFmpeg Heap Buffer Overflow in hvcC Box Writer via HEVC Muxing
FFmpeg before commit acf5d7c contains a heap buffer overflow in the hvcC box writer. When writing an HEVC configuration record with more NAL units of a single type than the count field can represent, the NAL unit count overflows, causing a heap buffer overflow. A crafted HEVC input file triggers the overflow during muxing.
Published Updated Sources: NVD, FFmpeg (CNA), GitHub, GitHub Security Advisory, SOCRadar CTI
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Exploit code
public exploit, none observed
EPSS
0%
ahead of 0% of scored CVEs
CVSS base
7.8
high · 2 sources
Remediation
The vendor's own words where we have them.
Upgrade FFmpeg to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Prioritize based on EPSS, PoC availability, and external exposure.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| FFmpeg | FFmpeg | 0 | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
High
Confidentiality
High
Integrity
High
Scope
Unchanged
Attack Complexity
Low
Attack Vector
Local
Privileges Req
None
User Interaction
Required
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | high | 1.8 | 5.9 | NVD, FFmpeg (CNA), GHSA |
| 8.5 | CVSS 4.0 | high | — | — | FFmpeg (CNA) |
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
What this weakness leads to
MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.
CWE-122 · Heap-based Buffer Overflow
- DoS: Crash, Exit, or Restart
- DoS: Resource Consumption (CPU)
- DoS: Resource Consumption (Memory)
- Execute Unauthorized Code or Commands
Mitigation: Pre-design: Use a language or compiler that performs automatic bounds checking.
Weakness & attack patterns
- CWE-122Heap-based Buffer Overflow
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
Public exploit
Capability, not use: code existing is a different claim from anyone running it.
Repositories
1
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 7.8 (AV:L)
Aug 19, 2026 · NVD
Initial · CVE published
Aug 19, 2026 · NVD
Added · GHSA-72cw-2m7j-25c8 published (high)
Aug 19, 2026 · GitHub Security Advisory
References
5 on the record
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781
Vendor Advisory
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24088
Vendor Advisory
- www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-in-hvcc-box-writer-via-hevc-muxing
Vendor Advisory
- nvd.nist.gov/vuln/detail/CVE-2026-75141
NVD
- github.com/advisories/GHSA-72cw-2m7j-25c8
Exploit, Third Party Advisory
Elsewhere on this site
- FFmpegevery CVE for this vendor
- Memory Corruptionsame class
- CWE-122other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2026-75141 is FFmpeg Heap Buffer Overflow in hvcC Box Writer via HEVC Muxing, a high vulnerability affecting FFmpeg from FFmpeg. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-75141. Public exploit evidence is: 1 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 7.8 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.