CVE-2026-42926 — MEDIUM (5.8)

Vulnerability Description

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.

CVSS Score

5.8

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-172

References

https://my.f5.com/manage/s/article/K000161131

FAQ

What is CVE-2026-42926?

CVE-2026-42926 is a vulnerability with a CVSS score of 5.8 (MEDIUM). 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 ...

How severe is CVE-2026-42926?

CVE-2026-42926 has been rated MEDIUM with a CVSS base score of 5.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42926?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.