CISA-confirmed known exploited vulnerability

CVE-2023-20109

Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerability

Cisco · IOS and IOS XE

Vulnerability details

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.

Added to CISA KEV: 2023-10-10

Ransomware campaign use: Unknown

CISA due date: 2023-10-31

Defensive guidance from CISA

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

This is the source's required-action field, not an independently validated patch procedure. Refer to the vendor for exact affected versions and fixes.

Source catalog date: 2026-11-06T19:44:45.1797Z · Last retrieved: 2026-11-06 21:02:26 UTC

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