Cisco Patches 34 Vulnerabilities Across Multiple Products

Cisco has rolled out fixes for 34 vulnerabilities spanning its Expressway Series, IOS XR, Snort 3, and Unified Communications product lines. The most severe flaw, CVE-2026-76466, is a critical remote code execution bug in Expressway caused by persistent cookies and weak client-certificate checks, letting an attacker reach the database service and issue RPC commands to run root-level commands on the device; it's resolved in Expressway version X15.5.20, which also closes eight CVE groupings and a medium-severity data-exposure issue. In Unified Communications products (including Emergency Responder, Prime Collaboration Deployment, Unified CM, CM IM&P, CM SME, and Unity Connection), Cisco closed nine CVEs, among them three critical bundled flaws — CVE-2026-76473, CVE-2026-76474, and CVE-2026-76475 — tied to resource control, authentication, and input-validation weaknesses. Snort 3 received 13 fixes, led by critical issues CVE-2026-20236 and CVE-2026-20043 involving faulty calculations and out-of-bounds writes, delivered in Snort 3 version 3.12.4.0 and in updates for related products like Cyber Vision, Meraki MX, Secure Firewall ASA/FMC/FTD, and UTD for IOS XE. Separately, Cisco patched a high-severity denial-of-service flaw in IOS XR (CVE-2026-76505) and a high-severity privilege-escalation issue in Secure Client's Posture module (CVE-2026-76462). Cisco states none of these 34 vulnerabilities have been observed being exploited in real attacks.