CVE-2026-42919: F5 BIG-IP · Stack-based Buffer Overflow
Affects F5 BIG-IPSource CVE Database V5
Not known to be exploited · CVSS 6.7 Medium · fixed in 21.0.0.1 : update F5 BIG-IP when convenient.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 21.0.0.1, 17.5.1.4, 17.1.3.1
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade F5 BIG-IP to 21.0.0.1, 17.5.1.4 or 17.1.3.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| F5BIG-IP | Affected
| Fixed in
|
AI-suggested
If you cannot patch yet, organizations should limit administrative access to trusted personnel only and monitor for unusual administrative activity. No vendor advisory or patch links are currently available, so follow F5's official channels for updates.
Description
CVE-2026-42919 is a stack-based buffer overflow vulnerability in F5 BIG-IP systems. It affects multiple versions including 21.0.0, 17.5.0, 17.1.0, and 16.1.0.