# CVE-2025-11964: OOBW in utf_16le_to_utf_8_truncated() in libpcap

> A buffer overflow in libpcap on Windows allows attackers to write beyond buffer boundaries when converting specific UTF-16 error messages, potentially leading to code execution or crashes.

- **Severity:** Low 1.9 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 31 Dec 2025
- **Updated:** 2 Jan 2026
- **Also known as:** GHSA-53h7-g6w8-rxxc

## What is CVE-2025-11964?

CVE-2025-11964 is a low-severity memory corruption vulnerability in The Tcpdump Group libpcap, published on 31 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

On Windows only, if libpcap needs to convert a Windows error message to UTF-8 and the message includes characters that UTF-8 represents using 4 bytes, utf_16le_to_utf_8_truncated() can write data beyond the end of the provided buffer.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2025-11964?


## How do I fix CVE-2025-11964?

No fix has been published for CVE-2025-11964 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-11964 being exploited?

There is no known exploitation of CVE-2025-11964 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-11964 and fix it if it is affected.

What it is: CVE-2025-11964 is a low-severity memory corruption vulnerability in The Tcpdump Group libpcap, published on 31 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-11964 in the wild and no public exploit code.

Affected product: The Tcpdump Group libpcap. 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-2025-11964/ (Markdown: https://insights.sbomify.com/CVE-2025-11964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-11964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-11964
- OSV: https://osv.dev/vulnerability/CVE-2025-11964

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-11964/
Summaries are generated and may contain mistakes; the official description above is the record.