# CVE-2026-8836: lwip: A vulnerability was found in lwIP up to 2.2.1

CVE-2026-8836 is fixed in 3 products on 1 platform, first by liblwip0 2.1.2+dfsg1-4ubuntu0.1~esm1, released May 18, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-8836
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0110
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 18, 2026

## Description

A vulnerability was found in lwIP up to 2.2.1. Affected is the function snmp_parse_inbound_frame of the file src/apps/snmp/snmp_msg.c of the component snmpv3 USM Handler. Performing a manipulation of the argument msgAuthenticationParameters results in stack-based buffer overflow. The attack may be initiated remotely. The patch is named 0c957ec03054eb6c8205e9c9d1d05d90ada3898c. It is suggested to install a patch to address this issue. Two separate issue reports were submitted to the project. Their processing was merged as a duplicate.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | liblwip0 Ubuntu 20.04 LTS (focal) | 2.1.2+dfsg1-4ubuntu0.1~esm1 | [liblwip0 2.1.2+dfsg1-4ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-liblwip0-2.1.2-dfsg1-4ubuntu0.1-esm1.md) | May 18, 2026 |
| Linux | liblwip0 Ubuntu 22.04.1 LTS (jammy) | 2.1.3+dfsg1-1ubuntu0.1~esm1 | [liblwip0 2.1.3+dfsg1-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-liblwip0-2.1.3-dfsg1-1ubuntu0.1-esm1.md) | May 18, 2026 |
| Linux | liblwip0t64 Ubuntu 24.04.5 LTS (noble) | 2.2.0+dfsg1-6.1ubuntu0.1~esm1 | [liblwip0t64 2.2.0+dfsg1-6.1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-liblwip0t64-2.2.0-dfsg1-6.1ubuntu0.1-esm1.md) | May 18, 2026 |
| Linux | liblwip0t64 Ubuntu 26.04.1 LTS (resolute) | 2.2.1+dfsg1-4ubuntu0.1~esm1 | [liblwip0t64 2.2.1+dfsg1-4ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-liblwip0t64-2.2.1-dfsg1-4ubuntu0.1-esm1.md) | May 18, 2026 |
| Linux | lwip Debian 13.5 (trixie) | 2.2.1+dfsg1-1+deb13u1 | [DEBIAN-CVE-2026-8836](https://patchblox.com/security/data/fix/linux/debian-cve-2026-8836.md) | May 18, 2026 |
| Linux | lwip Debian 14 | 2.2.1+dfsg1-5 | [DEBIAN-CVE-2026-8836](https://patchblox.com/security/data/fix/linux/debian-cve-2026-8836.md) | May 18, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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