Cisco Unified Communications Manager (CUCM, formerly CallManager) 5.1 before 5.1(2), and Unified CallManager 5.0, allow remote attackers to cause a denial of service (kernel panic) via a flood of SIP INVITE messages to UDP port 5060, which triggers resource exhaustion, aka CSCsi75822.
Conclusion & alert: CVE-2007-5537 is rated Moderate Risk (58.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.98%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 1.48% | 1.98% | +0.50% |
| 2 | 2025-03-30 | 1.13% | 1.48% | +0.35% |
| 3 | 2025-03-29 | — | 1.13% | — |
Full EPSS history (11 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.8 | 2.0 | HIGH |
|
10.0 | 6.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cisco | unified_callmanager | 5.0 | cpe:2.3:a:cisco:unified_callmanager:5.0:*:*:*:*:*:*:* |
| cisco | unified_communications_manager | <= 5.1\(2\) | cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:*:*:*:* |