🔐 CVE Alert

CVE-2026-20281

HIGH 7.5

Cisco Desk Phone 9800 Series, IP Phone 7800 and 8800 Series, and Video Phone 8875 with SIP Software Denial of Service Vulnerability

CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-401
Vendor cisco
Product cisco session initiation protocol (sip) software
Ecosystems
Industries
NetworkingTelecommunications
Published Sep 2, 2026
Last Updated Sep 2, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Affected Versions

Cisco / Cisco Session Initiation Protocol (SIP) Software
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

References

NVD ↗ CVE.org ↗ EPSS Data ↗
sec.cloudapps.cisco.com: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-phone-dos-txMYNRzv