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CVE-2026-28755

MEDIUM CVSS 4.0: 5.3 EPSS 0.01%
Updated Mar 26, 2026
F5
Parameter Value
CVSS 5.3 (MEDIUM)
Affected Versions 0.5.13 — 1.29.7
Fixed In 1.28.3
Type CWE-863 (Incorrect Authorization)
Vendor F5
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption

CVSS Vector v4.0

Vulnerable Products 14

Configuration From (including) Up to (excluding)
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r33:*:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r34:*:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r36:*:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:*
F5 Nginx_Plus
cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:*
F5 Nginx_Open_Source
cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*
0.5.13 <= 0.9.7
F5 Nginx_Open_Source
cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*
1.27.2 1.28.3
F5 Nginx_Open_Source
cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*
1.29.0 1.29.7