# CVE-2026-15185: GPAC MP4Box vobsub.c vobsub_read_idx out-of-bounds

> A local attacker can trigger an out-of-bounds read in GPAC MP4Box via crafted input, potentially causing crashes or information disclosure.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Jul 2026
- **Updated:** 9 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-15185, GHSA-fp8c-v4q6-8572, UBUNTU-CVE-2026-15185

## What is CVE-2026-15185?

CVE-2026-15185 is a medium-severity memory corruption vulnerability in GPAC, published on 9 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was determined in GPAC 26.03-DEV. This affects the function vobsub_read_idx of the file /src/media_tools/vobsub.c of the component MP4Box. Executing a manipulation of the argument num_langs can lead to out-of-bounds read. The attack needs to be launched locally. The exploit has been publicly disclosed and may be utilized. This patch is called 532097084729a936bcdf6a27c41003f3bd7dc3ff. It is best practice to apply a patch to resolve this issue. Two different commits were applied to fix this issue.

Weakness: CWE-125 (Out-of-bounds Read), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-15185?


## How do I fix CVE-2026-15185?

No fix has been published for CVE-2026-15185 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15185 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15185 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15185 and fix it if it is affected.

What it is: CVE-2026-15185 is a medium-severity memory corruption vulnerability in GPAC, published on 9 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15185 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-2026-15185/ (Markdown: https://insights.sbomify.com/CVE-2026-15185/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15185
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15185
- OSV: https://osv.dev/vulnerability/CVE-2026-15185

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15185/
Summaries are generated and may contain mistakes; the official description above is the record.