Contact Zero

CVE-2026-93302

wolfssl wolfssl

score 15HIGH 8.3

Summary

MatchTrustedPeer ignores the public key used, leading to forged CA clones passing verification. Affected builds are any that enable the macro WOLFSSL_TRUST_PEER_CERT and load CA certificates with wolfSSL_CTX_trust_peer_cert() or wolfSSL_trust_peer_cert(). The peer must know the certificates being loaded to either of those APIs to take advantage of the issue. When OPENSSL_COMPATIBLE_DEFAULTS is also defined this widens the affected API to include all CA certificate loading. Both macros are defined when using autoconf builds such as (nginx, haproxy, stunnel, wpas, apache httpd, hitch, bind, rsyslog, ffmpeg, all, distro). When the certificate is listed as a trusted peer certificate the issue previously allowed for a malicious (D)TLS server to bypass authentication once knowing which CA’s the client would accept. This also affects mutual authentication cases where the client knows which CA’s the server has loaded. If building with any of these configurations and using (D)TLS where the loaded CA’s could be known and authentication of the peer is desired, users should either: update to the latest wolfSSL version, apply the fix patch, or use the configure flag --disable-openssl-compatible-defaults and not load CA’s with wolfSSL_CTX_trust_peer_cert() or wolfSSL_trust_peer_cert() to mitigate the issue.

Published 2026-09-27 · first seen here 2026-10-10

Analysis & write-ups

No technical write-up from a research team yet. Contact Zero checks Unit 42, Google/Mandiant, Microsoft, Talos, CrowdStrike, Rapid7, watchTowr and others several times a day, plus NVD and CISA reference links.

Where it shows in your logs

Server or web application · Authentication bypass or missing authorisation low confidence

What to look for

Data sources

Web server and WAF logs · ATT&CK DS0015 Application Log Content

Sentinel
W3CIISLogAppServiceHTTPLogsAzureDiagnostics (Application Gateway / Front Door WAF)_Im_WebSession
Splunk
Web.Webms:iis:autoaccess_combinedWAF / proxy sourcetypes
CrowdStrike
Falcon Next-Gen SIEM: third-party web / WAF / proxy logs

Process creation · ATT&CK DS0009 Process Creation

Sentinel
DeviceProcessEventsSecurityEvent (4688)Sysmon Event ID 1_Im_ProcessCreate
Splunk
Endpoint.ProcessesXmlWinEventLog:Microsoft-Windows-Sysmon/OperationalWinEventLog:Security (4688)
CrowdStrike
ProcessRollup2SyntheticProcessRollup2

File creation · ATT&CK DS0022 File Creation

Sentinel
DeviceFileEventsSysmon Event ID 11_Im_FileEvent
Splunk
Endpoint.FilesystemSysmon Event ID 11
CrowdStrike
NewExecutableWrittenNewScriptWritten*FileWritten events

Network connections · ATT&CK DS0029 Network Connection Creation / Network Traffic Flow

Sentinel
DeviceNetworkEventsCommonSecurityLog (firewall)_Im_NetworkSession
Splunk
Network_Traffic.All_TrafficFirewall sourcetypes (pan:traffic, fortigate_traffic, cisco:asa)
CrowdStrike
NetworkConnectIP4NetworkReceiveAcceptIP4NetworkConnectIP6

Authentication and sessions · ATT&CK DS0028 Logon Session Creation / DS0002 User Account Authentication

Sentinel
SigninLogsSecurityEvent (4624, 4625, 4648)DeviceLogonEventsIdentityLogonEvents_Im_Authentication
Splunk
Authentication.Authenticationpan:globalprotectVPN sourcetypes
CrowdStrike
UserLogonUserLogonFailed2Falcon Identity Protection events

Account and group changes · ATT&CK DS0002 User Account Creation / Modification

Sentinel
SecurityEvent (4720, 4728, 4732, 4756)AuditLogsIdentityDirectoryEvents
Splunk
Change.All_Changes (Account_Management)WinEventLog:Security (4720, 4732)
CrowdStrike
UserAccountCreatedUserAccountAddedToGroup

A generic baseline worked out from the product type and weakness (CWE-295), not a detection. Check table and field names against your environment. Hunt queries for Sigma, Splunk, Sentinel and CrowdStrike are coming.

References