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Vulnerability record · CVE-2026-40460 · published 13 May 2026

CVE-2026-40460: F5 dos authentication bypass by spoofing vulnerability

F5 · Dos

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.

6.9 CVSS 4.0 Medium EPSS 0.38% · top 70.2% CWE-290 · Authentication bypass by spoofing
6.9CVSS 4.0 base score
0.38%EPSS exploitation probability, 30 days
NoNot in CISA KEV
7Affected product versions listed by NVD
1References
29 Jun 2026Last modified by NVD

Description

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/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:

Affected products

7 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://my.f5.com/manage/s/article/K000161068 Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-40460), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.