CISA KEV catalog
Confirmed active exploitation.
Listed in CISA's catalog of Known Exploited Vulnerabilities: attackers are using it in real attacks. Patch it with priority.
- Name
- Cisco IOS Software Integrated Services Module for VPN Denial-of-Service Vulnerability
- Added to catalog
- Remediation due date (US federal)
- Required action
- Apply updates per vendor instructions.
Description
A vulnerability in the crypto engine of the Cisco Integrated Services Module for VPN (ISM-VPN) running Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient handling of VPN traffic by the affected device. An attacker could exploit this vulnerability by sending crafted VPN traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to hang or crash, resulting in a DoS condition. Cisco Bug IDs: CSCvd39267.
Affected products
cisco: ios; cisco: 1000 integrated services router; cisco: 1100-4g\/6g integrated services router; cisco: 1100-4g integrated services router; cisco: 1100-4gltegb integrated services router; cisco: 1100-4gltena integrated services router; cisco: 1100-4p integrated services router; cisco: 1100-6g integrated services router; cisco: 1100-8p integrated services router; cisco: 1100-lte integrated services router; cisco: 1100 integrated services router; cisco: 1101-4p integrated services router; cisco: 1101 integrated services router; cisco: 1109-2p integrated services router; cisco: 1109-4p integrated services router
References7
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/c… Vendor Advisory
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/c… Vendor Advisory
- www.securityfocus.com/bid/103559 Broken LinkThird Party AdvisoryVDB Entry
- www.securitytracker.com/id/1040585 Broken LinkThird Party AdvisoryVDB Entry
- www.securityfocus.com/bid/103559 Broken LinkThird Party AdvisoryVDB Entry
- www.securitytracker.com/id/1040585 Broken LinkThird Party AdvisoryVDB Entry
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=… US Government Resource
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 7% percentile: 94 · as of 10 November 2026
- CWE
- CWE-399
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