On 2025-09-29, CISA added CVE-2025-20352 (Cisco IOS and IOS XE) to its Known Exploited Vulnerabilities (KEV) Catalog [2]. The vulnerability is listed in the catalog as "Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability" [2]. CISA requires remediation in accordance with vendor mitigation instructions; see the original text in the body for specific requirements [2].
Backfill: this event became public on Sep 29, 2025 and we added it on Nov 10, 2026. It is not a new event.
CISA Adds Cisco IOS and IOS XE Vulnerability CVE-2025-20352 to Known Exploited Vulnerabilities Catalog
1 min read
- Disclosed
- Sep 29, 2025
- Published
- Nov 10, 2026
- Last updated
- Nov 8, 2026
- CVSS basis
- Our assessment
- 40.6%, higher than 99% of CVEs
- Exploitation and patch status
- ExploitedKEV
- Attack vector
- Vulnerability status
- Actor type
- Motivation
On this page
30-second summary
What happened
Who is affected
Industries mainly affected: Government, Cross-industry
What to do nowOur advice
CISA requires remediation in accordance with vendor mitigation instructions; see the original text in the body for specific requirements [2]
Timeline
Technical details
CISA KEV Listing Record
On 2025-09-29, CISA added CVE-2025-20352 to the catalog for Cisco IOS and IOS XE [2].
Original Technical Description
Cisco IOS and IOS XE contains a stack-based buffer overflow vulnerability in the Simple Network Management Protocol (SNMP) subsystem that could allow for denial of service or . A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system. [2]
Official Requirements
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. [2]
Individual Vulnerability Record
The U.S. National Vulnerability Database (NVD) provides an independent vulnerability record and description for CVE-2025-20352. [1]
References
Official / primary3
- [1]
“A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco”
- [2]
This site aggregates public information and is not security consulting advice. Test remediation steps before applying.