# CVE-2026-111271: libmodplug through 0.8.9.1 Heap Out-of-Bounds Read via CSoundFile::ReadAMS2

> Attackers can read adjacent heap memory or cause a crash in applications using libmodplug by providing crafted AMS audio files.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 15 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-109736, DEBIAN-CVE-2026-111271, ECHO-f04f-7544-666b, GHSA-pxwm-j3xc-rxqw, UBUNTU-CVE-2026-111271

## What is CVE-2026-111271?

CVE-2026-111271 is a medium-severity memory corruption vulnerability in Konstanty Bialkowski libmodplug, published on 15 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

libmodplug through 0.8.9.1 contains a heap-based out-of-bounds read vulnerability in CSoundFile::ReadAMS2() in src/load_ams.cpp that allows attackers to read adjacent heap memory via crafted AMS files. Attackers can supply an AMS module whose pattern effect bytes keep bit 7 set, driving the decoder past the input buffer and crashing any libmodplug consumer.

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

## Which versions are affected by CVE-2026-111271?


## How do I fix CVE-2026-111271?

Upgrade to a fixed version.

## Is CVE-2026-111271 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111271 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111271 and fix it if it is affected.

What it is: CVE-2026-111271 is a medium-severity memory corruption vulnerability in Konstanty Bialkowski libmodplug, published on 15 Oct 2026. It can only be exploited from the same machine or local network, 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-2026-111271 exists.

Affected product: Konstanty Bialkowski libmodplug. 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-2026-111271/ (Markdown: https://insights.sbomify.com/CVE-2026-111271/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111271
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111271
- OSV: https://osv.dev/vulnerability/CVE-2026-111271

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-111271/
Summaries are generated and may contain mistakes; the official description above is the record.