SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-5507

On F5 BIG-IP versions 13.0.0, 12.1.0-12.1.3.1, 11.6.1-11.6.2, or 11.5.1-11.5.5, vCMP guests running on VIPRION 2100, 4200 and 4300 series blades cannot correctly decrypt ciphertext from established SSL sessions with small MTU.

HIGH 7.5EPSS 1.09%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.09%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

On F5 BIG-IP versions 13.0.0, 12.1.0-12.1.3.1, 11.6.1-11.6.2, or 11.5.1-11.5.5, vCMP guests running on VIPRION 2100, 4200 and 4300 series blades cannot correctly decrypt ciphertext from established SSL sessions with small MTU.

CVSS 3.0
7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
1.09% probability · 65th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Affected
f5/big-ip local traffic manager · f5/big-ip application acceleration manager · f5/big-ip advanced firewall manager · f5/big-ip analytics · f5/big-ip access policy manager · f5/big-ip application security manager · f5/big-ip edge gateway · f5/big-ip global traffic manager · f5/big-ip link controller · f5/big-ip policy enforcement manager · f5/big-ip webaccelerator · f5/big-ip websafe · f5/big-ip domain name system
Source
f5sirt@f5.com
EPSS trend
0%3%5%27 October 2026: 1.09%27 October 202627 October 2026

EPSS 1.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.