CVE-2026-40460

Medium
6.5
0.05.010.0
Year
2026
Published
May 13, 2026
Known Affected Devices
0
CVSS Score
6.5

What is 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.

CVSS Vector Breakdown

CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
AV
Attack Vector
Network

Exploitable remotely over the network without requiring access to the local system.

AC
Attack Complexity
Low

No special conditions required. Exploit can be performed reliably and repeatedly.

PR
Privileges Required
None

No authentication required. Any anonymous user can exploit this vulnerability.

UI
User Interaction
None

No user interaction required. Exploit runs without any victim action.

S
Scope
Unchanged

Exploiting the vulnerability only affects the vulnerable component itself.

C
Confidentiality Impact
Low

Some sensitive information is disclosed, but attacker has limited access.

I
Integrity Impact
None

No integrity impact. Data cannot be modified.

A
Availability Impact
Low

Reduced performance or intermittent outages, but service remains available.

FAQ

How severe is CVE-2026-40460?

CVE-2026-40460 has a CVSS score of 6.5/10, rated as Medium. Review the affected products list and apply vendor patches.

What does the CVSS score mean for CVE-2026-40460?

CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-40460 scores 6.5/10 (Medium). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.

Which devices are affected by CVE-2026-40460?

The list of devices confirmed to be affected by CVE-2026-40460 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.

How do I fix or mitigate CVE-2026-40460?

Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.