# CVE-2026-86514: vgmstream txth-txtp txth.c sscanf stack-based overflow

> A stack-based buffer overflow in vgmstream allows remote attackers to execute arbitrary code or cause denial of service via crafted files.

- **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:** 8 Sep 2026
- **Updated:** 11 Sep 2026
- **Also known as:** GHSA-4679-29mh-67pg

## What is CVE-2026-86514?

CVE-2026-86514 is a medium-severity memory corruption vulnerability in vgmstream, published on 8 Sep 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 weakness has been identified in vgmstream up to r2117. This issue affects the function sscanf of the file src/meta/txth.c of the component txth-txtp. This manipulation causes stack-based buffer overflow. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks. Patch name: 4669d37a6af94866f6f0628678f9f90d46954e8b. To fix this issue, it is recommended to deploy a patch.

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-86514?


## How do I fix CVE-2026-86514?

No fix has been published for CVE-2026-86514 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86514 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86514 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86514 and fix it if it is affected.

What it is: CVE-2026-86514 is a medium-severity memory corruption vulnerability in vgmstream, published on 8 Sep 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-2026-86514 exists.

Affected product: vgmstream. 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-2026-86514/ (Markdown: https://insights.sbomify.com/CVE-2026-86514/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86514
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86514
- OSV: https://osv.dev/vulnerability/CVE-2026-86514

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86514/
Summaries are generated and may contain mistakes; the official description above is the record.