Skip to content
Fencer Vulns
medium 5.7

CVE-2025-59729 json

Heap-buffer-overflow read in FFmpeg DHAV get_duration

published 2025-10-06 13 mo ago modified 2026-10-19 21 d ago also EUVD-2025-32182

cvss
5.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

When parsing the header for a DHAV file, there's an integer underflow in offset calculation that leads to reading the duration from before the start of the allocated buffer.

If we load a DHAV file that is larger than MAX_DURATION_BUFFER_SIZE bytes (0x100000) for example 0x101000 bytes, then at [0] we have size = 0x101000. At [1] we have end_buffer_size = 0x100000, and at [2] we have end_buffer_pos = 0x1000.

The loop then scans backwards through the buffer looking for the dhav tag; when it is found, we'll calculate end_pos based on a 32-bit offset read from the buffer.

There is subsequently a check [3] that end_pos is within the section of the file that has been copied into end_buffer, but it only correctly handles the cases where end_pos is before the start of the file or after the section copied into end_buffer, and not the case where end_pos is within the the file, but before the section copied into end_buffer. If we provide such an offset, (end_pos - end_buffer_pos) can underflow, resulting in the subsequent access at [4] occurring before the beginning of the allocation.

We recommend upgrading to version 8.0 or beyond.

Patch / fix

  • FFmpeg FFmpeg 8.0
  • ffmpeg Alpine 3.24, Alpine 3.23 8.0-r0

alpine advisories ALPINE-CVE-2025-59729

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-59729 updated cvss 6.8

FFmpeg: FFmpeg: Integer underflow in DHAV file header parsing leads to out-of-bounds read

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.7 CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:L/VI:H/VA:N/SC:L/SI:H/SA:N
CNA 4.0 5.7 CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:L/VI:H/VA:N/SC:L/SI:H/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

Affected products

  • FFmpeg FFmpeg

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.