# CVE-2026-91087: GPAC Compositor media_object.c gf_mo_get_od_id use after free

> A remote attacker can trigger a use-after-free in GPAC's compositor, potentially leading to code execution or 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:** 15 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-w6cq-hc26-45wr, UBUNTU-CVE-2026-91087

## What is CVE-2026-91087?

CVE-2026-91087 is a medium-severity use after free vulnerability in GPAC, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw has been found in GPAC up to f1219cde. This vulnerability affects the function gf_mo_get_od_id of the file compositor/media_object.c of the component Compositor. Executing a manipulation can lead to use after free. The attack may be performed from remote. The exploit has been published and may be used. Upgrading to version abi-16.24 is able to resolve this issue. This patch is called e34f4ba349d55cd1849f0bcf4cf46552732e2db7. Upgrading the affected component is advised.

Weakness: CWE-416 (Use After Free), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-91087?


## How do I fix CVE-2026-91087?

No fix has been published for CVE-2026-91087 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-91087 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91087 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-91087 and fix it if it is affected.

What it is: CVE-2026-91087 is a medium-severity use after free vulnerability in GPAC, published on 15 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-2026-91087 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-2026-91087/ (Markdown: https://insights.sbomify.com/CVE-2026-91087/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-91087
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-91087
- OSV: https://osv.dev/vulnerability/CVE-2026-91087

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-91087/
Summaries are generated and may contain mistakes; the official description above is the record.