Authentication bypass via ignored OCSP revocation result
Published Mar 24, 2026 · Updated Mar 24, 2026
Incorrect authorization in F5 NGINX Open Source and NGINX Plus allows remote authenticated users to bypass client-certificate revocation. In ngx_stream_ssl_module, an OCSP result can identify the presented certificate as revoked while the stream TLS path still completes the handshake instead of rejecting it. The issue is reachable only when the stream server enables both ssl_verify_client on and ssl_ocsp on, preserving network access for a certificate that administrators have revoked.
Summary
What happened
Incorrect authorization in F5 NGINX Open Source and NGINX Plus allows remote authenticated users to bypass client-certificate revocation. In ngx_stream_ssl_module, an OCSP result can identify the presented certificate as revoked while the stream TLS path still completes the handshake instead of rejecting it. The issue is reachable only when the stream server enables both ssl_verify_client on and ssl_ocsp on, preserving network access for a certificate that administrators have revoked.
The record
- CVE
- CVE-2026-28755
- Published
- Mar 24, 2026
- Updated
- Mar 24, 2026
- Vendor
- F5 Networks
- Product
- NGINX Open Source
- Classifications
- CWE-863, T1078
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 24, 2026CVE publishedPublication date reported by the CVE source.
- Mar 24, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.27.2 <1.28.3
- Affected versionversion=1.29.0 <1.29.7
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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