CVE-2026-20124: Cisco IOS XE Software SNMP Denial of Service Vulnerability

Description

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to improper error handling when parsing SNMP requests. This vulnerability affects all versions of SNMP — Versions 1, 2c, and 3. An attacker could exploit this vulnerability by sending a malformed SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly. The attacker must have the SNMPv1 or v2c read-only or read-write community string or valid SNMPv3 user credentials on the affected device.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Cisco Cisco IOS XE Software

Default version status: unknown

17.2.1aaffected
3.18.7SPaffected
16.12.1yaffected
16.12.3saffected
16.7.1baffected
16.6.2affected
16.6.5affected
16.12.1waffected
3.18.4Saffected
16.9.1daffected
17.3.1affected
16.9.4caffected
16.7.1affected
17.2.1affected
16.6.8affected
16.9.1baffected
3.16.8Saffected
16.9.2saffected
16.12.4affected
16.12.3aaffected
17.1.1saffected
16.11.1aaffected
16.7.2affected
16.11.1baffected
16.9.1saffected
16.9.3haffected
16.9.1caffected
16.6.5aaffected
16.6.3affected
16.10.1faffected
17.2.1vaffected
16.8.1eaffected
16.9.3aaffected
16.12.1aaffected
16.12.1xaffected
3.16.10aSaffected
16.6.4saffected
16.10.1caffected
16.12.3affected
16.11.2affected
16.6.5baffected
16.12.2saffected
16.10.1baffected
16.7.3affected
16.6.7affected
16.9.6affected
16.9.2affected
3.16.10Saffected
16.10.1affected
16.12.1taffected
3.18.3bSPaffected
3.13.9Saffected
3.18.3aSPaffected
3.18.5SPaffected
16.9.1affected
16.8.1aaffected
3.18.8aSPaffected
16.9.3saffected
16.6.7aaffected
16.12.2affected
16.11.1affected
16.9.3affected
16.11.1saffected
16.12.1affected
3.16.9Saffected
17.1.1affected
17.1.2affected
16.10.1daffected
17.1.1taffected
16.9.4affected
16.8.3affected
16.12.2taffected
16.9.5affected
3.16.7Saffected
16.8.1saffected
16.10.1eaffected
16.8.2affected
16.6.4affected
16.8.1baffected
16.10.1aaffected
16.12.1zaffected
16.8.1caffected
16.9.1aaffected
3.16.7aSaffected
16.9.5faffected
16.6.4aaffected
16.10.1gaffected
3.13.10Saffected
16.8.1affected
16.6.6affected
16.9.2aaffected
16.8.1daffected
16.10.3affected
3.18.4SPaffected
3.18.6SPaffected
3.18.3SPaffected
16.7.1aaffected
16.11.1caffected
16.10.1saffected
17.2.1raffected
3.16.7bSaffected
17.1.1aaffected
16.10.2affected
16.12.2aaffected
3.16.6bSaffected
16.12.1caffected
16.12.1saffected
16.7.4affected
3.18.9SPaffected
17.2.2affected
16.9.8affected
16.9.7affected
17.1.3affected
17.3.1aaffected
17.3.2aaffected
16.12.5affected
17.3.1waffected
17.3.2affected
17.4.1affected
16.12.4aaffected
17.4.1aaffected
3.16.10bSaffected
17.3.1xaffected
17.3.3affected
16.6.9affected
17.2.3affected
17.5.1affected
16.12.1z1affected
16.12.5aaffected
17.4.1baffected
17.3.1zaffected
16.12.5baffected
17.4.2affected
17.3.3aaffected
17.3.5affected
17.3.4affected
17.5.1aaffected
16.12.6affected
17.6.1affected
16.12.1z2affected
16.6.10affected
17.3.4aaffected
17.6.1aaffected
17.7.1affected
17.6.1xaffected
17.6.2affected
16.12.6aaffected
17.3.4caffected
17.4.2aaffected
17.3.4baffected
17.7.1aaffected
16.12.7affected
17.8.1aaffected
17.6.3aaffected
17.6.3affected
17.7.2affected
17.7.1baffected
17.9.1waffected
17.3.5aaffected
17.6.1zaffected
16.12.8affected
17.8.1affected
17.9.1affected
17.6.4affected
17.3.5baffected
17.9.1aaffected
17.3.6affected
17.10.1affected
16.9.8aaffected
17.6.1z1affected
17.10.1aaffected
17.9.2affected
17.6.5affected
17.9.1xaffected
17.9.1yaffected
16.9.8baffected
17.3.7affected
17.9.2aaffected
17.9.3affected
16.12.9affected
17.11.1affected
17.10.1baffected
17.6.6affected
17.9.1x1affected
17.11.1aaffected
17.9.3aaffected
17.12.1affected
17.3.8affected
17.9.4affected
16.12.10affected
17.12.1waffected
17.9.1y1affected
17.12.1aaffected
17.9.5affected
17.13.1affected
17.12.1xaffected
17.12.2affected
17.14.1affected
17.9.4aaffected
17.3.8aaffected
17.6.6aaffected
17.6.5aaffected
17.6.7affected
16.12.10aaffected
17.15.1affected
17.13.1aaffected
17.12.2aaffected
16.12.11affected
17.12.3affected
17.12.1yaffected
17.12.1zaffected
17.9.5aaffected
17.14.1aaffected
17.9.5baffected
17.6.8affected
16.12.12affected
17.12.4affected
17.9.6affected
17.17.1affected
17.16.1affected
17.15.1waffected
17.12.3aaffected
17.9.5caffected
17.15.1aaffected
17.12.1z1affected
17.15.2affected
17.15.1baffected
17.9.5daffected
17.15.1xaffected
17.9.6aaffected
17.12.1z2affected
17.6.8aaffected
17.16.1aaffected
16.12.13affected
17.15.3affected
17.9.7affected
17.12.5affected
17.15.1yaffected
17.9.5eaffected
17.12.4aaffected
17.15.2aaffected
17.15.2caffected
17.15.2baffected
17.12.1z3affected
17.9.5faffected
17.12.4baffected
17.12.5aaffected
17.18.1affected
17.12.6affected
17.12.1z4affected
17.9.8affected
17.9.7aaffected
17.15.3aaffected
17.15.4affected
17.12.5baffected
17.15.3baffected
16.12.14affected
17.9.7baffected
17.12.5caffected
17.18.1aaffected
17.15.4aaffected
17.18.2affected
17.18.1waffected
17.15.4baffected
17.12.6aaffected
17.15.4caffected
17.9.9affected
17.12.5daffected
16.12.15affected
17.15.4s1affected
17.12.1z5affected
17.18.1xaffected
17.12.1z6affected
17.15.4daffected
17.12.6baffected
17.4.1caffected
17.18.1yaffected

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-snmp-dos-ZAqNm4MD ↗