NGINX

CVE-2026-28755: NGINX ngx_stream_ssl_module vulnerability

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_stream_ssl_module module due to the improper handling of revoked certificates when configured with the ssl_verify_client on and ssl_ocsp on directives, allowing the TLS handshake to succeed even after an OCSP check identifies the certificate as revoked.

Published

ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityMEDIUMCVSS 4.0 5.3
EPSS0.15%Chance of exploitation in 30 days
Public exploitNot tracked
FixAvailable

Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.

Affected and fixed versions

Product / branchFixed in
NGINX Open Source 1.291.29.7 or later
NGINX Open Source 1.271.28.3 or later
NGINX Plus R36R36 P3 or later
NGINX Plus R35R35 P2 or later
NGINX Plus R34* or later
NGINX Plus R33* or later

Always confirm against the vendor advisory, which lists every fixed hotfix.

What it is

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_stream_ssl_module module due to the improper handling of revoked certificates when configured with the ssl_verify_client on and ssl_ocsp on directives, allowing the TLS handshake to succeed even after an OCSP check identifies the certificate as revoked.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Sources

KEV status, EPSS score and vendor data refreshed automatically, last on 12 Oct 2026.

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