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.

The remote Ubuntu 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8423-1 advisory.

    It was discovered that lwIP contained a buffer overflow in the EAP authentication handling code. An     attacker could possibly use this issue to trigger a buffer overflow, resulting in arbitrary code execution     or a denial of service. This issue only affected Ubuntu 20.04 LTS. (CVE-2020-8597)

    It was discovered that lwIP incorrectly handled certain ICMPv6 or 6LoWPAN packets. An attacker could     possibly use this issue to trigger a buffer overflow, resulting in information disclosure. This issue only     affected Ubuntu 20.04 LTS. (CVE-2020-22283, CVE-2020-22284)

    It was discovered that lwIP did not properly validate certain SNMPv3 authentication parameters. An     attacker could possibly use this issue to trigger a stack-based buffer overflow, resulting in arbitrary     code execution or a denial of service. (CVE-2026-8836)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-8836)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
320846	Ubuntu 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : lwIP vulnerabilities (USN-8423-1)	Nessus	Ubuntu Local Security Checks	critical
315227	Linux Distros Unpatched Vulnerability : CVE-2026-8836	Nessus	Misc.	critical

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CVE-2026-8836

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