# CVE-2026-124030: GPAC through 26.07.0 Type Confusion via gf_sg_command_apply XMT Field-Replace


- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 6 Nov 2026
- **Updated:** 10 Nov 2026
- **Also known as:** GHSA-xx5j-3p7q-h39r, UBUNTU-CVE-2026-124030

## What is CVE-2026-124030?

CVE-2026-124030 is a medium-severity vulnerability in gpac, published on 6 Nov 2026. 

### Official description

GPAC through 26.07.0 contains a type confusion vulnerability in gf_sg_command_apply() in src/scenegraph/commands.c that fails to verify BIFS field-replace command types match target node fields. Attackers can supply a crafted XMT file opened with MP4Box, such as via chapter import, causing gf_sg_vrml_field_clone() to memcpy from invalid pointers and crash.

Weakness: CWE-843 (Access of Resource Using Incompatible Type)

## Which versions are affected by CVE-2026-124030?


## How do I fix CVE-2026-124030?

No fix has been published for CVE-2026-124030 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-124030 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124030 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-124030 and fix it if it is affected.

What it is: CVE-2026-124030 is a medium-severity vulnerability in gpac, published on 6 Nov 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124030 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-2026-124030/ (Markdown: https://insights.sbomify.com/CVE-2026-124030/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-124030
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124030
- OSV: https://osv.dev/vulnerability/CVE-2026-124030

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-124030/
Summaries are generated and may contain mistakes; the official description above is the record.