CVE-2026-8836 lwIP snmpv3 USM snmp_msg.c snmp_parse_inbound_frame stack-based overflow
Remote attackers can trigger a stack-based buffer overflow in the lwIP SNMPv3 USM handler, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-8836?
CVE-2026-8836 is a critical memory corruption vulnerability in lwIP, published on 18 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-8836?
How do I fix CVE-2026-8836?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-8836 being exploited?
There is no known exploitation of CVE-2026-8836 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as DEBIAN-CVE-2026-8836, GHSA-3w8m-3w76-f6mh, OESA-2026-2480, UBUNTU-CVE-2026-8836.