Medium severity · published Mar 24, 2026
CVE-2026-28755
NGINX ngx_stream_ssl_module vulnerability
5.4
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NO
NGINX Open Source · F5
1.29.0 before 1.29.7; 1.27.2 before 1.28.3 · source: vendor, NVD
NP
NGINX Plus · F5
R36 before R36 P3; R35 before R35 P2; R34; R33 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-28755
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-28755
Mitigation
https://my.f5.com/manage/s/article/K000160368
More from NGINX Open Source
8.2
CVE-2026-60005
NGINX ngx_http_slice_module vulnerability
8.2
CVE-2026-27654
NGINX ngx_http_dav_module vulnerability
8.1
CVE-2026-97205
NGINX ngx_http_core_module vulnerability
8.1
CVE-2026-93479
NGINX map directive and regex matching vulnerability
8.1
CVE-2026-15176
NGINX ngx_http_core_module vulnerability