# CVE-2026-92399: GPAC heap-based buffer overflow in WebSocket handler

Source: https://junglewise.ai/threats/cve-2026-92399-gpac-heap-based-buffer-overflow-in-websocket-handler  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-16. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-92399 · Severity: high · CVSS 7.3 · Published 2026-09-16

GPAC is a widely-used multimedia framework for video streaming and transcoding. A heap buffer overflow in its WebSocket message handler allows remote attackers to trigger memory corruption by sending a specially crafted WebSocket frame. Successful exploitation could lead to application crash, information disclosure, or arbitrary code execution.

Technologies: [Gpac](https://junglewise.ai/threats/technologies/gpac). Vendors: [Gpac](https://junglewise.ai/threats/vendors/gpac).

## Quick answers

**Is CVE-2026-92399 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-92399 being exploited in the wild.

**How severe is CVE-2026-92399?** High severity, with a CVSS score of 7.3, published 16 September 2026.

**Which products and versions are affected?** Gpac 26.07.0.

**Is there a fix for CVE-2026-92399?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-92399 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-92399?** Check whether you run Gpac at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A heap-based buffer overflow vulnerability exists in the rmt_client_handle_ws_frame function of src/utils/rmt_ws.c in GPAC version 26.07.0. The vulnerability is triggered by manipulation of the payload_size argument, which is not properly validated before being used in buffer operations. The attack is remotely exploitable without authentication, requiring only network access to a service using the vulnerable WebSocket handler. An attacker can craft and send a malicious WebSocket frame to trigger the overflow, potentially achieving code execution or denial of service. The issue is fixed in version abi-16.26 by commit 37bccbb30cf53a0e1a084cea9a1ce422b3ddfe12.

## Affected products

- GPAC GPAC 26.07.0

## Timeline

- 2026-09-16: disclosed

## References

- [https://github.com/gpac/gpac/](https://github.com/gpac/gpac/)
- [https://github.com/gpac/gpac/commit/37bccbb30cf53a0e1a084cea9a1ce422b3ddfe12](https://github.com/gpac/gpac/commit/37bccbb30cf53a0e1a084cea9a1ce422b3ddfe12)

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- [GPAC buffer overflow in DASH Client URL resolution](https://junglewise.ai/threats/cve-2026-103227-a-weakness-has-been-identified-in-gpac-up-to-26-07-0-affected-by)