https://github.com/net-snmp/net-snmp/security/advisories/GHSA-4389-rwqf-q9gq advises:
Net-SNMP snmptrapd vulnerability hardaker published GHSA-4389-rwqf-q9gq Dec 22, 2025 Package: Net-SNMP Affected versions: All Patched versions: 5.9.5, 5.10.pre2 Description =========== Impact ------- A specially crafted packet to an net-snmp snmptrapd daemon can cause a buffer overflow and the daemon to crash. Patches ------- Users of Net-SNMP's snmptrapd should upgrade immediately to Net-SNMP 5.9.5 or 5.10.pre2. Other workarounds ----------------- SNMP ports should never be open to public networks. There is no mitigation available other than ensuring ports to snmptrapd are appropriately firewalled or by upgrading to the most recent versions of the Net-SNMP software: 5.9.5 or 5.10.pre2. CVE Identifier -------------- This has been assigned a CVE identifier of CVE-2025-68615. Credits ------- This vulnerability was discovered by: buddurid working with Trend Micro Zero Day Initiative Severity: Critical 9.8 / 10 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
https://www.zerodayinitiative.com/advisories/ZDI-25-1181/ further notes:
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Net-SNMP. Authentication is not required to exploit this vulnerability. The specific flaw exists within the SnmpTrapd service, which listens on UDP port 162 by default. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the service account.
