SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-15372

A vulnerability in the MACsec Key Agreement (MKA) using Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) functionality of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to bypass authentication and pass…

HIGH 8.1EPSS 0.75%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.75%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A vulnerability in the MACsec Key Agreement (MKA) using Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) functionality of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to bypass authentication and pass traffic through a Layer 3 interface of an affected device. The vulnerability is due to a logic error in the affected software. An attacker could exploit this vulnerability by connecting to and passing traffic through a Layer 3 interface of an affected device, if the interface is configured for MACsec MKA using EAP-TLS and is running in access-session closed mode. A successful exploit could allow the attacker to bypass 802.1x network access controls and gain access to the network.

CVSS 3.0
8.1 HIGHCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
0.75% probability · 55th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-284
Affected
cisco/ios xe
Source
psirt@cisco.com
EPSS trend
0%3%5%27 October 2026: 0.75%27 October 202627 October 2026

EPSS 0.7% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.