CVE-2026-42926

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.

Scoring

Severity
MEDIUM
CVSS base score
6.3
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N
EPSS probability
0.35%
CWE
CWE-172
Published
2026-05-13
Last modified
2026-05-13

Affected products

Weakness type

Related vulnerabilities

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