CVE-2026-28755 — Incorrect Authorization in F5 Nginx Open Source

CWE-863 — Incorrect AuthorizationCWE-295 — Improper Certificate Validation11 documents10 sources
Severity
5.3MEDIUMNVD
EPSS
0.0%
top 97.55%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
3
F5 NginxF5 Nginx Open SourceF5 Nginx Plus
Timeline
PublishedMar 24
Latest updateApr 17

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:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Affected Packages6 packages

▶CVEListV5f5/nginx_open_source1.29.0 — 1.29.7+1
▶NVDf5/nginx_open_source1.27.2 — 1.28.3+2
▶CVEListV5f5/nginx_plusR36 — R36 P3+3
▶NVDf5/nginx_plus4 versions+3
▶Alpinef5/nginx< 1.28.3-r0+1

🔴Vulnerability Details

5
VulDB
F5 NGINX Open Source/NGINX Plus ngx_stream_ssl_module authorization (K000160368 / Nessus ID 306672)↗2026-04-17
▶
OSV
CVE-2026-28755: 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 co↗2026-03-24
▶
CVEList
NGINX ngx_stream_ssl_module vulnerability↗2026-03-24
▶
GHSA
GHSA-hgfr-jmpr-2p89: 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 co↗2026-03-24
▶
OSV
CVE-2026-28755: 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 co↗2026-03-24
▶

📋Vendor Advisories

4
Red Hat
NGINX: NGINX: Certificate revocation bypass when OCSP is enabled↗2026-03-24
▶
F5
CVE-2026-28755: NGINX Plus and NGINX Open Source have a vulnerability in the ngx_stream_ssl_module module due to the improper handlin...↗2026-03-24
▶
Microsoft
NGINX ngx_stream_ssl_module vulnerability↗2026-03-10
▶
Debian
CVE-2026-28755: nginx - NGINX Plus and NGINX Open Source have a vulnerability in the ngx_stream_ssl_modu...↗2026
▶

🕵️Threat Intelligence

1
Wiz
CVE-2026-28755 Impact, Exploitability, and Mitigation Steps | Wiz↗
▶
CVE-2026-28755 — Incorrect Authorization in F5 | cvebase