CVE intelligence and bounded remediation

CVE-2026-40460 — F5 Dos security vulnerability

Medium CVSS 6.9

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.

Severity
Medium
CVSS
6.9 (4.0)
Published
2026-05-13
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-290

Affected products

  • f5 / dos
  • f5 / dos / 4.8.0
  • f5 / nginx_gateway_fabric
  • f5 / nginx_ingress_controller
  • f5 / nginx_instance_manager
  • f5 / nginx_open_source

Showing 6 representative product identities from 13 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

General vulnerability remediation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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