# CVE-2026-5317: Nothings stb stb_vorbis.c start_decoder out-of-bounds write

> Remote attackers can trigger an out-of-bounds write in the stb_vorbis decoder, potentially leading to code execution or crashes.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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:** A user has to click or open something
- **Fix available:** No
- **Published:** 2 Apr 2026
- **Updated:** 2 Apr 2026
- **Also known as:** DEBIAN-CVE-2026-5317, GHSA-8mhm-8wmq-8793, UBUNTU-CVE-2026-5317

## What is CVE-2026-5317?

CVE-2026-5317 is a medium-severity memory corruption vulnerability in Nothings stb, published on 2 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A security flaw has been discovered in Nothings stb up to 1.22. This affects the function start_decoder of the file stb_vorbis.c. The manipulation results in out-of-bounds write. The attack may be performed from remote. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-787 (Out-of-bounds Write), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-5317?

It affects 1 product.


Products: Nothings Stb Vorbis.c.

## How do I fix CVE-2026-5317?

No fix has been published for CVE-2026-5317 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5317 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5317 exists.

## Other vulnerabilities in Nothings stb

- [CVE-2023-45676](https://insights.sbomify.com/CVE-2023-45676/): Multi-byte write heap buffer overflow in start_decoder in stb_vorbis (high 7.3)
- [CVE-2023-45677](https://insights.sbomify.com/CVE-2023-45677/): Heap buffer out of bounds write in start_decoder in stb_vorbis (high 7.3)
- [CVE-2023-45679](https://insights.sbomify.com/CVE-2023-45679/): Attempt to free an uninitialized memory pointer in vorbis_deinit in stb_vorbis (high 7.3)
- [CVE-2023-45681](https://insights.sbomify.com/CVE-2023-45681/): Out of bounds heap buffer write in stb_vorbis (high 7.3)
- [CVE-2023-45675](https://insights.sbomify.com/CVE-2023-45675/): 0 byte write heap buffer overflow in start_decoder in stb_vorbis (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5317 and fix it if it is affected.

What it is: CVE-2026-5317 is a medium-severity memory corruption vulnerability in Nothings stb, published on 2 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5317 exists.

Affected product: Nothings stb. 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-2026-5317/ (Markdown: https://insights.sbomify.com/CVE-2026-5317/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5317
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5317
- OSV: https://osv.dev/vulnerability/CVE-2026-5317

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-5317/
Summaries are generated and may contain mistakes; the official description above is the record.