Cisco Unity Connection Vulnerability Exploits SSRF Attacks

EXECUTIVE SUMMARY:

Cisco released security patches for multiple high-severity vulnerabilities affecting several enterprise products including Unity Connection and SG350 switches. The flaws could allow remote attackers to perform server-side request forgery attacks execute arbitrary code as root and trigger denial-of-service (DoS) conditions. The vulnerabilities stem from insufficient validation of user-supplied input and crafted HTTP requests. Cisco confirmed there are no workarounds for some of the issues and urged users to upgrade to fixed software versions immediately to reduce the risk of exploitation.[emaillocker id="1283"]

• CVE-2026-20034 with a CVSS score of 8.8 could allow an authenticated remote attacker to execute arbitrary code as root on affected Cisco Unity Connection devices through crafted API requests.
• CVE-2026-20035 with a CVSS score of 8.8 could allow authenticated attackers to perform server-side request forgery (SSRF) attacks through affected Cisco Unity Connection systems.

Organizations using affected Cisco products should review the latest security updates and apply the necessary patches to reduce exposure. Monitoring exposed services and restricting unnecessary access can also help minimize potential attack opportunities.

RECOMMENDATION:

• We recommend you to update Cisco Unity Connection to a fixed release (12.5 or later), or apply patch file: ciscocm.cuc.V15_CSCwq36774-CSCwq36834_C0277-1.zip for version 15.0, and 14SU5 for version 14.0.

REFERENCES:

The following reports contain further technical details:
https://securityaffairs.com/191808/breaking-news/cisco-patches-high-severity-flaws-enabling-ssrf-code-execution-attacks.html