# CVE-2026-92399: GPAC WebSocket rmt_ws.c rmt_client_handle_ws_frame heap-based overflow

> A heap-based buffer overflow in GPAC's WebSocket handler allows remote attackers to execute arbitrary code or cause denial of service.

- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-mmf7-gvjr-4mjf, UBUNTU-CVE-2026-92399

## What is CVE-2026-92399?

CVE-2026-92399 is a medium-severity memory corruption vulnerability in GPAC, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-122 (Heap-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-92399?


## How do I fix CVE-2026-92399?

No fix has been published for CVE-2026-92399 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-92399 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-92399 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-92399 and fix it if it is affected.

What it is: CVE-2026-92399 is a medium-severity memory corruption vulnerability in GPAC, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-92399 exists.

Affected product: GPAC. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-92399/ (Markdown: https://insights.sbomify.com/CVE-2026-92399/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-92399
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-92399
- OSV: https://osv.dev/vulnerability/CVE-2026-92399

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-92399/
Summaries are generated and may contain mistakes; the official description above is the record.