CVE intelligence and bounded remediation
CVE-2026-42926 — F5 Nginx Gateway Fabric security vulnerability
When NGINX Open Source is configured to proxy HTTP/2 traffic by setting proxy_http_version to 2, and also uses proxy_set_body, an attacker may be able to inject frame headers and payload bytes to the upstream peer. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
- Severity
- Medium
- CVSS
- 6.3 (4.0)
- Published
- 2026-05-13
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-172
Affected products
- f5 / nginx_gateway_fabric
- f5 / nginx_open_source
- f5 / nginx_instance_manager
- f5 / nginx_ingress_controller
Showing 4 representative product identities from 7 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
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.