Critical F5 BIG-IP Vulnerability Exploited as Zero-Day
Source SecurityWeek
Exploited in the wild · KEV due 25 Sep 2026 : apply the vendor's fix or mitigations to BIG-IP now.
Data as of 5 Nov 2026, 23:24 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 22 Sep 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: evidence found.
Listed in CISA KEV the same day as disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by F5, Inc.
, 45 hours before disclosure
CVE published
on cve.org
, t = 0
In Threat Radar
record ingested
, 16 minutes after disclosure
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, the same day as disclosure
KEV remediation due
US federal deadline
, 3 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| F5BIG-IP | Affected
| Fixed in– |
AI-suggested
F5 has released official hotfixes for the affected BIG-IP APM versions (21.1.0, 17.5.0 to 17.5.1, and 17.1.0 to 17.1.3). Organizations should apply these hotfixes immediately to mitigate the risk. CISA has added this vulnerability to its Known Exploited Vulnerabilities list and mandates patching within three days for federal agencies. Monitoring for the published indicators of compromise is recommended to detect potential exploitation. No other mitigation steps are indicated by the vendor advisory.
Description
A critical remote code execution vulnerability (CVE-2026-94127) affects F5 BIG-IP Access Policy Manager (APM) when configured as an OAuth Authorization Server. Unauthenticated attackers can exploit this zero-day flaw by sending malicious traffic to vulnerable BIG-IP appliances. The vulnerability impacts specific versions of BIG-IP APM and has been actively exploited in the wild. F5 has released hotfixes addressing the issue, and CISA has added it to its Known Exploited Vulnerabilities list, urging rapid patching.