# CVE-2026-124309: Fraunhofer HHI VVdeC before 3.2.1 Heap Out-of-Bounds Read via SEIReader::xParseSEIScalableNesting


- **Severity:** Medium 6.9 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 7 Nov 2026
- **Updated:** 12 Nov 2026
- **Also known as:** GHSA-w892-xhp2-gg6x

## What is CVE-2026-124309?

CVE-2026-124309 is a medium-severity vulnerability in fraunhoferhhi vvdec, published on 7 Nov 2026. 

### Official description

Fraunhofer HHI VVdeC before 3.2.1 contains a heap out-of-bounds read vulnerability in SEIReader::xParseSEIScalableNesting that allows attackers to read past heap allocations by casting the SEI wrapper object instead of its payload. Attackers can supply a crafted VVC bitstream with a scalable nesting SEI containing a nested buffering period SEI to crash the decoder or copy adjacent heap memory.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-124309?


## How do I fix CVE-2026-124309?

No fix has been published for CVE-2026-124309 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-124309 being exploited?

There is no known exploitation of CVE-2026-124309 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-124309 and fix it if it is affected.

What it is: CVE-2026-124309 is a medium-severity vulnerability in fraunhoferhhi vvdec, published on 7 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-124309 in the wild and no public exploit code.

Affected product: fraunhoferhhi vvdec. 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-2026-124309/ (Markdown: https://insights.sbomify.com/CVE-2026-124309/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-124309
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124309
- OSV: https://osv.dev/vulnerability/CVE-2026-124309

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-124309/
Summaries are generated and may contain mistakes; the official description above is the record.