# CVE-2025-11961: OOBR and OOBW in pcap_ether_aton() in libpcap

> Out-of-bounds read and write in libpcap's pcap_ether_aton function can lead to memory corruption and potential code execution.

- **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:** Yes
- **Published:** 31 Dec 2025
- **Updated:** 2 Jan 2026
- **Also known as:** ALPINE-CVE-2025-11961, AZL-73335, AZL-73344, AZL-73373, AZL-73379, BELL-CVE-2025-11961, DEBIAN-CVE-2025-11961, ECHO-5e37-6bb1-4b05, GHSA-x25x-vjrm-h7qq, MGASA-2026-0005, OESA-2026-1109, OESA-2026-1110, OESA-2026-1111, OESA-2026-1112, OESA-2026-1113, OESA-2026-1114, OESA-2026-1207, SUSE-SU-2026:0036-1, SUSE-SU-2026:0053-1, SUSE-SU-2026:0062-1, SUSE-SU-2026:0063-1, SUSE-SU-2026:0575-1, SUSE-SU-2026:20048-1, SUSE-SU-2026:20120-1, SUSE-SU-2026:20153-1, UBUNTU-CVE-2025-11961, openSUSE-SU-2026:10032-1, openSUSE-SU-2026:20075-1

## What is CVE-2025-11961?

CVE-2025-11961 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

pcap_ether_aton() is an auxiliary function in libpcap, it takes a string argument and returns a fixed-size allocated buffer.  The string argument must be a well-formed MAC-48 address in one of the supported formats, but this requirement has been poorly documented.  If an application calls the function with an argument that deviates from the expected format, the function can read data beyond the end of the provided string and write data beyond the end of the allocated buffer.

Weakness: CWE-126 (Buffer Over-read), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2025-11961?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libpcap` | SUSE:Linux Enterprise Micro 5.2 | All versions | 1.9.1-150300.3.6.1 |
| `libpcap` | SUSE:Linux Enterprise Micro 5.3 | All versions | 1.10.1-150400.3.9.1 |
| `libpcap` | SUSE:Linux Enterprise Micro 5.4 | All versions | 1.10.1-150400.3.9.1 |
| `libpcap` | SUSE:Linux Enterprise Micro 5.5 | All versions | 1.10.1-150400.3.9.1 |
| `libpcap` | SUSE:Linux Enterprise Module for Basesystem 15 SP7 | All versions | 1.10.5-150700.3.7.1 |
| `libpcap` | SUSE:Linux Enterprise Module for Package Hub 15 SP7 | All versions | 1.10.5-150700.3.7.1 |
| `libpcap` | SUSE:Linux Enterprise Server 16.0 | All versions | 1.10.5-160000.4.1 |
| `libpcap` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 1.8.1-10.9.1 |
| `libpcap` | SUSE:Linux Enterprise Server for SAP applications 16.0 | All versions | 1.10.5-160000.4.1 |
| `libpcap` | SUSE:Linux Micro 6.0 | All versions | 1.10.4-4.1 |
| `libpcap` | SUSE:Linux Micro 6.2 | All versions | 1.10.5-160000.4.1 |
| `libpcap` | openSUSE:Leap 15.6 | All versions | 1.10.4-150600.3.9.1 |
| `libpcap` | openSUSE:Leap 16.0 | All versions | 1.10.5-160000.4.1 |
| `libpcap` | openSUSE:Tumbleweed | All versions | 1.10.6-1.1 |

## How do I fix CVE-2025-11961?

Apply the vendor's patch.

## Is CVE-2025-11961 being exploited?

There is no known exploitation of CVE-2025-11961 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-11961 and fix it if it is affected.

What it is: CVE-2025-11961 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-2025-11961 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-2025-11961/ (Markdown: https://insights.sbomify.com/CVE-2025-11961/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-11961
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-11961
- OSV: https://osv.dev/vulnerability/CVE-2025-11961

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-11961/
Summaries are generated and may contain mistakes; the official description above is the record.