Vulnerability · Published May 18, 2026 · Assigned by VulDB
CVE-2026-8836lwIP snmpv3 USM snmp_msg.c snmp_parse_inbound_frame stack-based overflow
Critical 9.8
In plain English
A critical-severity stack buffer overflow in lwIP. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 66% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | lwip | no fix listed | DEBIAN-CVE-2026-8836 |
| Debian:13 | lwip | 2.2.1+dfsg1-1+deb13u1 | DEBIAN-CVE-2026-8836 |
| Debian:14 | lwip | 2.2.1+dfsg1-5 | DEBIAN-CVE-2026-8836 |
| Ubuntu:25.10 | lwip | no fix listed | UBUNTU-CVE-2026-8836 |
| Ubuntu:26.10 | lwip | no fix listed | UBUNTU-CVE-2026-8836 |
Affected products (as reported)
Weakness: CWE-121, CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
References
- VDB-364474 | lwIP snmpv3 USM snmp_msg.c snmp_parse_inbound_frame stack-based overflow vdb-entry, technical-description
- VDB-364474 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- CVE-2026-8836 | CVE Analysis and Report third-party-advisory
- Submit #829798 | lwIP 2.1.0 Stack-based Buffer Overflow third-party-advisory
- https://savannah.nongnu.org/bugs/?68055 broken-link
- https://cgit.git.savannah.gnu.org/cgit/lwip.git/commit/?id=0c957ec03054eb6c8205e9c9d1d05d90ada3898c broken-link, patch
- https://github.com/lwip-tcpip/lwip/commit/0c957ec03054eb6c8205e9c9d1d05d90ada3898c patch
- https://savannah.nongnu.org/bugs/?68194 broken-link