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.
Weakness: CWE-772
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco IOS XE Software | Routing & Switching | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco IOS XE Software
Vendor advisory
cisco-sa-iosxe-snmp-dos-ZAqNm4MD
Cisco IOS XE Software SNMP Denial of Service Vulnerability
Cisco’s rating: High (advisory CVSS 7.7) · Published Aug 5, 2026
Bug ID: CSCws90638
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from