Answer in brief
CVE-2026-20281 records a Unknown severity vulnerability in Cisco Desk Phone 9800 Series, IP Phone 7800 and 8800 Series, and Video Phone 8875 with SIP Software Denial of Service Vulnerability. The current sources do not mark it as known exploited. The current feed maps Cisco/Cisco Session Initiation Protocol (SIP) Software (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Cisco/Cisco Session Initiation Protocol (SIP) Software (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Cisco/Cisco Session Initiation Protocol (SIP) Softwaregeneric | 12.1(1)SR1 || 11.5(1) || 10.3(2) || 10.2(2) || 10.3(1) || 10.3(1)SR4 || 11.0(1) || 10.4(1)SR2 3rd Party || 11.7(1) || 12.1(1) || 11.0(0.7) MPP || 9.3(4) 3rd Party || 12.5(1)SR2 || 10.2(1)SR1 || 9.3(4)SR3 3rd Party || 10.2(1) || 12.5(1) || 10.3(1)SR2 || 11-0-1MSR1-1 || 10.4(1) 3rd Party || 12.5(1)SR1 || 11.5(1)SR1 || 10.1(1)SR2 || 12.0(1)SR2 || 12.6(1) || 10.3(1.11) 3rd Party || 12.0(1) || 12.0(1)SR1 || 9.3(3) || 12.5(1)SR3 || 10.3(1)SR4b || 9.3(4)SR1 3rd Party || 10.3(1)SR5 || 10.1(1.9) || 10.3(1.9) 3rd Party || 9.3(4)SR2 3rd Party || 10.3(1)SR1 || 10.3(1)SR3 || 10.1(1)SR1 || 12.0(1)SR3 || 12.6(1)SR1 || 12.7(1) || 10.3(1)SR6 || 12.8(1) || 12.7(1)SR1 || 11.0(2)SR1 || 11.0(4) || 11.0(2) || 11.0(4)SR3 || 11.0(5) || 11.0(3)SR2 || 11.0(3)SR4 || 11.0(3)SR3 || 11.0(2)SR2 || 11.0(4)SR1 || 11.0(5)SR3 || 11.0(3) || 11.0(5)SR2 || 11.0(3)SR6 || 11.0(5)SR1 || 11.0(4)SR2 || 11.0(3)SR1 || 11.0(3)SR5 || 11.0(6) || 12.8(1)SR1 || 12.8(1)SR2 || 14.0(1) || 14.0(1)SR1 || 11.0(6)SR1 || 10.3(1)SR7 || 14.0(1)SR2 || 14.1(1) || 14.0(1)SR3 || 11.0(6)SR2 || 14.1(1)SR1 || 14.1(1)SR2 || 11.0(6)SR4 || 14.2(1) || 14.2(1)SR1 || 11.0(6)SR5 || 14.1(1)SR3 || 14.2(1)SR2 || 3.1(1) || 3.0(1) || 2.3(1) || 2.3(1)SR1 || 2.2(1) || 2.1(1) || 2.0(1) || 14.2(1)SR3 || 3.1(1)SR1 || 14.3(1) || 3.2(1) || 14.3(1)SR1 || 14.2(1)SR4 || 3.3(1) || 11.0(6)SR6 || 14.3(1)SR2 || 3.4(1) || 14.3(1)SR3 || 3.5(1) || 11.0(6)SR7 || 3.5(1)SR1 || 14.4(1) || 3.6(1) || 4.0(1) || 14.4(1)SR1 || 4.1(1) || 14.4(1)SR2 || 4.1(1)SR1 | Not reported |
Published upstream
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 2, 2026
A vulnerability in Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 and 8800 Series, and Cisco Video Phone 8875 that are running Cisco Session Initiation Protocol (SIP) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper memory management when an affected device processes HTTP packets. An attacker could exploit this vulnerability by sending a continuous stream of crafted HTTP packets to the device. A successful exploit could allow the attacker to cause the affected device to continuously consume memory, resulting in a DoS condition. A manual reboot of the device is required to recover from this condition. Note: For this vulnerability to be exploitable, the phone must be registered to Cisco Unified Communications Manager (Unified CM) and have Web Access enabled. Web Access is disabled by default.
Quoted source text, attributed separately from HOL analysis.