CVE-2026-42926: F5 Nginx Gateway Fabric

Medium severity, CVSS 5.8. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• F5 Nginx Gateway Fabric: from 1.3.0, up to and including 1.6.2; from 2.0.0, up to and including 2.6.0
• F5 Nginx Ingress Controller: from 3.5.0, up to and including 3.7.2; from 4.0.0, up to and including 4.0.1; from 5.0.0, up to and including 5.4.2
• F5 Nginx Instance Manager: from 2.16.0, up to and including 2.22.0
• F5 Nginx Open Source: from 1.29.4, up to and including 1.30.0

Published 2026-05-13. Last modified 2026-06-18.