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Fencer Intel
high 8.7

CVE-2026-42406 json

BIG-IP and BIG-IQ privilege escalation vulnerability

published 5mo ago modified 14d ago also EUVD-2026-29997

cvss
8.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

A vulnerability exists in BIG-IP and BIG-IQ systems where a highly privileged, authenticated attacker with at least the Certificate Manager role can modify configuration objects that allow running arbitrary commands.     Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Patch / fix

  • F5 BIG-IP 17.1.3.2, 17.5.1.6, 21.0.0.2, 21.1.0

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
5mo ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 8.7 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
CNA 4.0 8.5 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
CNA 4.0 8.5 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • F5 BIG-IP
  • F5 BIG-IQ

Classification

Weakness
  • CWE-267 Privilege Defined With Unsafe Actions

References

Sources

Fencer Intel 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.