CVE-2025-20144

A vulnerability in the hybrid access control list (ACL) processing of IPv4 packets in Cisco IOS XR Software could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to incorrect handling of packets when a specific configuration of the hybrid ACL exists. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to bypass a configured ACL on the affected device. For more information, see the section of this advisory. Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability. It has a CVSS v3.1 base score of 4.0 (MEDIUM).

CVE-2025-20144 has a CVSS v3.1 score of 4.0 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

CVE-2025-20144 affects products from cisco, specifically: ios_xr, ncs_540-12z20g-sys-a, ncs_540-12z20g-sys-d, ncs_540-24q2c2dd-sys, ncs_540-24q8l2dd-sys, ncs_540-24z8q2c-sys, ncs_540-28z4c-sys-a, ncs_540-28z4c-sys-d, ncs_540-6z14s-sys-d, ncs_540-6z18g-sys-a, ncs_540-6z18g-sys-d, ncs_540-acc-sys, ncs_540-fh-agg, ncs_540-fh-csr-sys, ncs_540x-12z16g-sys-a, ncs_540x-12z16g-sys-d, ncs_540x-16z4g8q2c-a, ncs_540x-16z4g8q2c-d, ncs_540x-16z8q2c-d, ncs_540x-4z14g2q-a, ncs_540x-4z14g2q-d, ncs_540x-6z18g-sys-a, ncs_540x-6z18g-sys-d, ncs_540x-8z16g-sys-a, ncs_540x-8z16g-sys-d, ncs_540x-acc-sys, ncs_5501, ncs_5501-se, ncs_5502, ncs_5502-se, ncs_5508, ncs_5516, ncs_560-4, ncs_560-7, ncs_57b1-5dse-sys, ncs_57b1-6d24-sys, ncs_57c1-48q6-sys, ncs_57c3-mod-sys, ncs_57d2-18dd-sys. Check the affected products table above for specific version ranges.

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.