Vulnerability in F5 Dos
CVE-2026-40460
When NGINX Plus or NGINX Open Source are configured to use the HTTP/3 QUIC module, an attacker may be able to spoof their source IP address allowing for bypass of authorization or bypass of rate limiting. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L.
EPSS exploit prediction
EPSS: 0.004 (30.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- F5 Dos — versions 4.8.0
- F5 nginx Gateway Fabric
- F5 nginx Ingress Controller
- F5 nginx Instance Manager
- F5 nginx Open Source — versions 1.31.0, 1.26.0
- F5 nginx Open Source
- F5 nginx Plus — versions R37, R36, R32
- F5 nginx Plus
- F5 Waf
Weakness classification (CWE)
References
- my.f5.com/manage/s/article/K000161068 (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-40460?
- CVE-2026-40460 is a medium-severity vulnerability in F5 Dos, classified under Authentication Bypass by Spoofing. CVSS score: 6.5/10. Published 2026-05-13.
- How severe is CVE-2026-40460?
- Medium severity. CVSS v3 base score is 6.5 out of 10.