In BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, and 14.1.0-14.1.2.6, a BIG-IP virtual server with a Session Initiation Protocol (SIP)…

published 2020-08-26 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-27080

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.0%; EPSS 1.0% chance of exploitation in 30 days, percentile 64%
public exploits: 0; none known

In BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, and 14.1.0-14.1.2.6, a BIG-IP virtual server with a Session Initiation Protocol (SIP) ALG profile, parsing SIP messages that contain a multi-part MIME payload with certain boundary strings can cause TMM to free memory to the wrong cache.

Patch / fix

fixed in 11

f5 big-ip_access_policy_manager 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_advanced_firewall_manager 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_analytics 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_application_acceleration_manager 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_application_security_manager 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_domain_name_system 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_fraud_protection_service 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_global_traffic_manager 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_link_controller 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_local_traffic_manager 14.1.2.7, 15.0.1.4, 15.1.0.5
f5 big-ip_policy_enforcement_manager 14.1.2.7, 15.0.1.4, 15.1.0.5

Exploit prediction

1.04% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

n/a BIG-IP

Classification

Weakness

CWE-404 Improper Resource Shutdown or Release

References

support.f5.com /csp/article/K42830212
vendor-advisory

Sources

CVE List CVE-2020-5926
NVD CVE-2020-5926

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary