Vulnerability · Published May 13, 2026 · Assigned by f5

CVE-2026-40460NGINX ngx_quic_module vulnerability

Medium 6.5

In plain English

A medium-severity authentication bypass by spoofing in NGINX Open Source from F5. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.4%top 68.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Alpine:v3.21	nginx	1.26.3-r1	ALPINE-CVE-2026-40460
Alpine:v3.22	nginx	1.28.3-r1	ALPINE-CVE-2026-40460
Alpine:v3.23	nginx	1.28.3-r1	ALPINE-CVE-2026-40460
Alpine:v3.24	nginx	1.30.1-r0	ALPINE-CVE-2026-40460
Debian:13	nginx	1.26.3-3+deb13u5	DEBIAN-CVE-2026-40460
Debian:14	nginx	1.30.0-4	DEBIAN-CVE-2026-40460
Ubuntu:25.10	nginx	1.28.0-6ubuntu1.4	UBUNTU-CVE-2026-40460
Ubuntu:26.04:LTS	nginx	1.28.3-2ubuntu1.2	UBUNTU-CVE-2026-40460

Affected products (as reported)

Vendor	Product	Versions
F5	NGINX Plus	R36 – before R36 P4R32 – before R32 P6
F5	NGINX Open Source	1.26.0 – before 1.30.1

Weakness: CWE-290 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

References

https://my.f5.com/manage/s/article/K000161068 vendor-advisory, patch