7.5

CVE-2026-20281: cisco cisco session initiation protocol (sip) software

CVSS: 7.5v3.1HighAwaiting analysis
Published 02-09-2026Last modified 02-09-2026
Open JSON

Vulnerability summary

CVE-2026-20281 is a high (CVSS 7.5) vulnerability in cisco cisco session initiation protocol (sip) software. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 29.1% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.37%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 02-09-2026
    PublishedVulnerability first disclosed.
  2. 02-09-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.37%

Chance of exploitation in the next 30 days

Percentile

29%

Versus all other CVEs

30-day change

+0.04 pp

From 0.33% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.37%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco1 product
  • cisco session initiation protocol (sip) software12.1(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

1 vendor · 1 product

References

1 links