High severity · published Aug 5, 2026
CVE-2026-20124
Cisco IOS XE Software SNMP Denial of Service Vulnerability
7.7
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 43% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
IX
IOS XE · Cisco
3.13.9s; 3.13.10s; 3.16.6bs; 3.16.7as; 3.16.7bs; 3.16.7s; +34 more · source: NVD
CI
Cisco IOS XE Software · Cisco
17.2.1a; 3.18.7SP; 16.12.1y; 16.12.3s; 16.7.1b; 16.6.2; +34 more · source: vendor
Affected product
IX
IOS XE
Cisco
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