ACTIVELY EXPLOITED
CVE-2023-20109: Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerability
| Vendor | Cisco |
|---|---|
| Product | IOS and IOS XE |
| Actively exploited | Yes |
| Added to CISA KEV | 10 Oct 2023 |
| CISA federal deadline | 31 Oct 2023 |
| Weakness (CWE) | CWE-787 |
Required action (CISA's text)
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Description (NVD)
Cisco IOS and IOS XE contain an out-of-bounds write vulnerability in the Group Encrypted Transport VPN (GET VPN) feature that could allow an authenticated, remote attacker who has administrative control of either a group member or a key server to execute malicious code or cause a device to crash.
SOURCES
Other Cisco flaws
- CVE-2026-20320: Cisco BroadWorks Improper Restriction of XML External Entity Reference Vulnerability
- CVE-2026-76418: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
- CVE-2026-76519: Cisco Secure Email Gateway Relative Path Traversal Vulnerability
- CVE-2026-76504: Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
- CVE-2026-76460: Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.