Vulnerability report

Exploitation Attempts Observed Confirmed Confidence In CISA KEV

CVE-2026-94127

BIG-IP APM OAuth vulnerability

F5 / BIG-IP · affected before Hotfix-BIGIP-21.1.0.2.0.30.22-ENG

Watch CVE-2026-94127 Browse KEV feed
Severity
CVSS 9.3 · Critical
Confidence
Confirmed
Exploit status
Exploitation Attempts Observed in the Wild
EPSS
26.6%
First observed
05 Oct 2026
Last observed
23 Oct 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-94127 is an unauthenticated BIG-IP APM OAuth vulnerability.

Have exploitation attempts been observed?

Yes. Previdian sensors have observed 4 exploitation attempts, 3 unique attacker IPs, and 3 countries targeting CVE-2026-94127. First observed Oct 05, 2026; last observed Oct 23, 2026. Listed in CISA KEV. Also reported by third-party sources. Confidence is confirmed.

Who is affected?

F5 / BIG-IP, including affected before Hotfix-BIGIP-21.1.0.2.0.30.22-ENG, affected before Hotfix-BIGIP-17.5.1.9.0.160.12-ENG, and affected before Hotfix-BIGIP-17.1.3.5.0.41.14-ENG.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

BIG-IP APM OAuth vulnerability

When a BIG-IP APM access policy and an OAuth profile are configured on a virtual server, specific malicious traffic can lead to remote code execution (RCE). This vulnerability is only present when BIG-IP APM is configured as an OAuth Authorization Server. Deployments using APM strictly as an OAuth Client / Resource Server (without OAuth authorization server profiles configured) are not affected by this vulnerability.

Impact: This vulnerability allows an unauthenticated attacker to perform remote code execution. The BIG-IP system in Appliance mode is also vulnerable. This is a data plane issue; there is no control plane exposure.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

F5 Affected
BIG-IP
Before Hotfix-BIGIP-21.1.0.2.0.30.22-ENG Before Hotfix-BIGIP-17.5.1.9.0.160.12-ENG Before Hotfix-BIGIP-17.1.3.5.0.41.14-ENG
View vendor advisory (opens in new tab)
Published
22 Sep 2026
Exploitation Attempts Reported
22 Sep 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

edge cisa

CVE References

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation Attempts Observed in the Wild

F5 Security Advisories

Recorded 22 Sep 2026

A trusted third party reported exploitation attempts.

Exploitation Attempts Observed

Previdian sensor

First observed 05 Oct 2026

Previdian sensors observed exploitation attempts targeting this vulnerability.

Proof of concept available

GitHub

Recorded 24 Sep 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
F5 Security Advisories First 2026-09-22 16:21 UTC
CISA 2026-09-22 19:50 UTC
CVE 2026-09-22 20:01 UTC
The Hacker News 2026-09-23 08:31 UTC
CERT Polska 2026-09-23 14:22 UTC
Security Affairs 2026-09-23 18:21 UTC
TheRegister 2026-09-23 18:21 UTC
SOCRadar 2026-09-25 08:20 UTC
Previdian Sensors 2026-10-05 09:25 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

Previdian Sensor Observations

Previdian sensor observations are exploitation attempts targeting this vulnerability. They do not show that the target was vulnerable or that the attempt succeeded. The cards and chart show volume, unique attackers, and daily activity.

4

Attempts observed

3

Unique attacker IPs

3

Attacker countries

AE · CN · ID

1

Sensors observed

CVE-2026-94127 exploitation attempts over the last 37 days

Daily events observed by Previdian sensors

Updated 09 Nov 2026

0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4 Oct 12 Oct 20 Oct 28 Oct 9 Nov

First observed 05 Oct 2026 · Last observed 23 Oct 2026

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
1
1
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

Learn about Pro API access

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

9.3 Critical

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

EPSS

26.6%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Heap-based Buffer Overflow CWE-122

Recent mention · SOCRadar

Top RCE Vulnerabilities

Top RCE Vulnerabilities A remote code execution (RCE) vulnerability is a software flaw that lets an attacker run their own code on a target system from a remote location. Exploiting vulnerabilities like this is now the m

Read full advisory

All CVSS Scores

CVSS v4.0 9.3 Critical

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS v3.1 9.8 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

All Mentions

Recent mention · F5 Security Advisories

K12201527: Overview of F5 security notifications

F5 Security Advisories · 22 Sep 2026

Security Advisory Description F5 is making two changes to our approach going forward: hardened releases are moving to a six-week cadence, and we are pausing regular security notifications. For more information, please see this blog: Our first hardened release cycle: What we learned and how we’re changing. F5 discloses security vulnerabilities and security exposures for F5 products in security notifications. 2026 security notifications Older security notifications Note: To be notified about F5 security notifications, subscribe to F5 Security Announcements. These announcements include links...

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

watchtowrlabs/watchTowr-vs-f5-bigip-PreAuth-RCE-CVE-2026-94127

github · Created 2026-09-24 19:22:13 UTC · 2 stars · AI assessment 85%

Timeline

From disclosure to observed exploitation attempts

  1. 09:21 UTC

    Indicators of compromise added (4)

    Indicators of compromise recorded

  2. 09:21 UTC

    Observed by Previdian sensors

    Previdian sensors observed exploitation attempts targeting this vulnerability.

  3. 08:20 UTC

    KEV confirmed by SOCRadar

    Exploitation attempts reported by an external source

  4. 19:22 UTC

    Public PoC available

    Public proof-of-concept code published

  5. 18:21 UTC

    KEV confirmed by TheRegister

    Exploitation attempts reported by an external source

  6. 18:21 UTC

    KEV confirmed by Security Affairs

    Exploitation attempts reported by an external source

  7. 14:22 UTC

    KEV confirmed by CERT Polska

    Exploitation attempts reported by an external source

  8. 08:31 UTC

    KEV confirmed by The Hacker News

    Exploitation attempts reported by an external source

  9. 20:01 UTC

    KEV confirmed by CVE

    Exploitation attempts reported by an external source

  10. 19:50 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  11. 16:21 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party report of exploitation attempts

  12. 15:20 UTC

    Added to the Previdian watchlist

    Pro and Enterprise Watch users had 5 hours of early warning before CISA KEV. Also 1 hour before Previdian KEV.

  13. 14:17 UTC

    CVE published

    Vulnerability disclosed publicly

  14. 17:39 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-94127

Sample API response 
{
  "cve_id": "CVE-2026-94127",
  "confidence": "Confirmed",
  "cvss_score": 9.3,
  "cvss_estimated": false,
  "epss_score": 0.2655,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 4, "sensors": 1 }
}