CVE-2026-53423
Fix: membraneframework/membrane_mp4_plugin@56373d1CVE-2026-53423 is a CWE-770 vulnerability in membrane_mp4_plugin. O3 Security confirms whether CVE-2026-53423 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Unauthenticated denial-of-service via BEAM atom table exhaustion in membrane_mp4_plugin
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-53423.
Real-World Exposure
membrane_mp4_pluginReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.
Description
Allocation of Resources Without Limits or Throttling vulnerability in membraneframework membrane_mp4_plugin allows unauthenticated denial-of-service via BEAM atom table exhaustion.
The MP4 box header parser converts each 4-byte box name to an atom using String.to_atom/1 without validation. 'Elixir.Membrane.MP4.Container.Header':parse_box_name/1 in lib/membrane_mp4/container/header.ex interns every box name encountered while 'Elixir.Membrane.MP4.Container.Header':parse/1 walks the input. BEAM atoms are never garbage-collected, so each unique attacker-controlled 4-byte name is a permanent allocation. A crafted MP4 of approximately 8 MB containing roughly 1.1 million boxes with distinct non-standard names exhausts the atom table (default ceiling around 1,048,576 atoms), aborting the entire BEAM node and taking down all applications running on it.
This issue affects membrane_mp4_plugin from 0.3.0 before 0.36.7.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💧Hex | membrane_mp4_plugin | all versions | 0.36.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for membrane_mp4_plugin. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update membrane_mp4_plugin to 0.36.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-53423 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-53423 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-53423. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-53423 in your dependencies?
O3 detects CVE-2026-53423 across Hex dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.