A vulnerability in the call-handling functionality of Session Initiation Protocol (SIP) Software for Cisco IP Phone 7800 Series and 8800 Series could allow an unauthenticated, remote attacker to cause an affected phone to reload unexpectedly, resulting in a temporary denial of service (DoS) condition. The vulnerability is due to incomplete error handling when XML data within a SIP packet is parsed. An attacker could exploit this vulnerability by sending a SIP packet that contains a malicious XML payload to an affected phone. A successful exploit could allow the attacker to cause the affected phone to reload unexpectedly, resulting in a temporary DoS condition.
Conclusion & alert: CVE-2019-1635 is rated Moderate Risk (58.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.97%). 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 | 0.98% | 1.97% | +0.99% |
| 2 | 2025-12-12 | 1.16% | 0.98% | -0.18% |
| 3 | 2025-03-30 | — | 1.16% | — |
Full EPSS history (11 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 7.5 | 3.0 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 7.8 | 2.0 | HIGH |
|
10.0 | 6.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cisco | ip_conference_phone_7832_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_conference_phone_7832_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_conference_phone_7832_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_conference_phone_7832_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_conference_phone_7832_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_conference_phone_7832_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_conference_phone_7832_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_conference_phone_7832_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_conference_phone_8832_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_conference_phone_8832_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_conference_phone_8832_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_conference_phone_8832_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_conference_phone_8832_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_conference_phone_8832_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_conference_phone_8832_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_conference_phone_8832_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_7811_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_7811_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_7811_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_7811_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_7811_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_7811_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_7811_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_7811_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_7821_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_7821_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_7821_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_7821_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_7821_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_7821_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_7821_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_7821_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_7841_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_7841_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_7841_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_7841_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_7841_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_7841_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_7841_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_7841_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_7861_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_7861_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_7861_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_7861_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_7861_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_7861_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_7861_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_7861_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_8811_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_8811_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_8811_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_8811_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_8811_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_8811_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_8811_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_8811_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_8841_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_8841_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_8841_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_8841_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_8841_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_8841_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_8841_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_8841_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_8845_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_8845_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_8845_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_8845_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_8845_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_8845_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_8845_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_8845_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_8851_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_8851_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_8851_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_8851_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_8851_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_8851_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_8851_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_8851_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_8861_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_8861_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_8861_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_8861_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_8861_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_8861_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_8861_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_8861_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | ip_phone_8865_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:ip_phone_8865_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | ip_phone_8865_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:ip_phone_8865_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | ip_phone_8865_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:ip_phone_8865_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | ip_phone_8865_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:ip_phone_8865_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | unified_ip_8831_conference_phone1_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:unified_ip_8831_conference_phone1_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | unified_ip_8831_conference_phone1_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:unified_ip_8831_conference_phone1_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | unified_ip_8831_conference_phone1_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:unified_ip_8831_conference_phone1_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | unified_ip_8831_conference_phone1_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:unified_ip_8831_conference_phone1_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | unified_ip_8831_conference_phone_for_third-party_call_control2_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:unified_ip_8831_conference_phone_for_third-party_call_control2_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | unified_ip_8831_conference_phone_for_third-party_call_control2_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:unified_ip_8831_conference_phone_for_third-party_call_control2_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | unified_ip_8831_conference_phone_for_third-party_call_control2_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:unified_ip_8831_conference_phone_for_third-party_call_control2_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | unified_ip_8831_conference_phone_for_third-party_call_control2_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:unified_ip_8831_conference_phone_for_third-party_call_control2_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | wireless_ip_phone_8821_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:wireless_ip_phone_8821_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | wireless_ip_phone_8821_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:wireless_ip_phone_8821_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | wireless_ip_phone_8821_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:wireless_ip_phone_8821_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | wireless_ip_phone_8821_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:wireless_ip_phone_8821_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |
| cisco | wireless_ip_phone_8821-ex_firmware | 9.3\(4\)sr3 | cpe:2.3:o:cisco:wireless_ip_phone_8821-ex_firmware:9.3\(4\)sr3:*:*:*:*:*:*:* |
| cisco | wireless_ip_phone_8821-ex_firmware | 10.3\(1\)sr4b | cpe:2.3:o:cisco:wireless_ip_phone_8821-ex_firmware:10.3\(1\)sr4b:*:*:*:*:*:*:* |
| cisco | wireless_ip_phone_8821-ex_firmware | 11.0\(4\)sr2 | cpe:2.3:o:cisco:wireless_ip_phone_8821-ex_firmware:11.0\(4\)sr2:*:*:*:*:*:*:* |
| cisco | wireless_ip_phone_8821-ex_firmware | 12.1\(1\)sr1 | cpe:2.3:o:cisco:wireless_ip_phone_8821-ex_firmware:12.1\(1\)sr1:*:*:*:*:*:*:* |