CVE-2026-15576

CVE-2026-15576 is an improper authentication vulnerability in the agent receiver of Checkmk versions prior to 2.5.0p10 . An unauthenticated remote attacker can bypass mutual TLS (mTLS) client certificate verification on relay endpoints by supplying a fixed placeholder identity in the request URL....

CVE-2026-15576 Agent receiver accepts mTLS requests without a client certificate

Improper authentication in the agent receiver of Checkmk 2.5.0p10 allows an unauthenticated remote attacker to bypass mutual TLS client certificate verification of relay endpoints by supplying a fixed placeholder identity in the request URL, resulting in limited impact on integrity and...

CVE-2026-16837

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to improper handling of a missing SSL client certificate...

CVE-2026-16837

IBM AIX 7.2 and 7.3, and PowerVM VIOS 4.1, mishandle a missing SSL client certificate, allowing an unauthenticated remote attacker to trigger denial of service. CVSS 3.1 scores this HIGH (7.5), with no confidentiality or integrity impact. No patch or exploitation details are provided in the docum...

CVE-2026-16837 Vulnerabilities in IBM AIX and PowerVM VIOS

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to improper handling of a missing SSL client certificate...

CVE-2026-74882

The PHP package openssl_encrypt before version 1.4.0 ships with an insecure default that trusts the entire RFC 1918 private address space in IntegrityProxyConfig::trusted_proxies. An attacker on a private network can forge client certificate headers to bypass mTLS authentication whenever ProxyAut...

CVE-2026-66760

SAP Approuter does not correctly validate client certificates in certain callback flows. An attacker with low privileges, holding a certificate from the same trusted authority with matching subject values, could bypass the identity check. This complexity makes the attack difficult to execute...

EUVD-2026-55878

SAP Approuter does not correctly validate client certificates in certain callback flows. An attacker with low privileges, holding a certificate from the same trusted authority with matching subject values, could bypass the identity check. This complexity makes the attack difficult to execute...

CVE-2026-66760

Technical details about CVE-2026-66760 are not publicly available in the provided documents beyond what is described in the Initial Description; monitor for updates.

UBUNTU-CVE-2026-67294

FreeRDP before 3.29.0 improperly validates the Extended Key Usage EKU purpose of the peer certificate during client-side server TLS authentication. In x509utilsverify, when server-purpose X509PURPOSESSLSERVER verification fails, the code falls back to client-purpose and any-purpose verification, ...

EUVD-2026-47794

When PROXY protocol v2 is used on the Unix domain socket path, roles derived from X.509 client certificates may not be validated against the configured tlsCATrusts allow-list. This can result in unintended role assignments following MONGODB-X509 authentication. Affected scenarios require local...

CVE-2026-13067 tlsCATrusts Role Restriction Not Enforced via PROXY Protocol v2 on Unix Domain Socket

When PROXY protocol v2 is used on the Unix domain socket path, roles derived from X.509 client certificates may not be validated against the configured tlsCATrusts allow-list. This can result in unintended role assignments following MONGODB-X509 authentication. Affected scenarios require local...

JLSEC-2026-737 TLS 1.3 post-handshake authentication (PHA) issue where a server could accept a client's Finished...

TLS 1.3 post-handshake authentication PHA issue where a server could accept a client's Finished message without the client having sent a Certificate and CertificateVerify. The post-handshake-auth exemption that allows an empty/absent peer certificate was only intended for the initial handshake, b...

Exploit for Improper Authentication in Apache Tomcat

CVE-2026-29145 – Everything Apache Tomcat CLIENTCERT + OCS...

etcd: gRPC client listener does not enforce `--client-crl-file` certificate revocation

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SUSE CVE-2026-8932

libcurl would reuse a previously created connection even when some mTLS config related option had been changed that should have prohibited reuse. libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. However, some TLS...

UBUNTU-CVE-2026-59818

etcd is a distributed key-value store for the data of a distributed system. Prior to 3.5.32 and 3.6.13, when etcd is configured with --listen-client-http-urls to split HTTP and gRPC client endpoints onto separate listeners, the --client-crl-file Certificate Revocation List is not enforced on the...

CVE-2026-59818

etcd is a distributed key-value store for the data of a distributed system. Prior to 3.5.32 and 3.6.13, when etcd is configured with --listen-client-http-urls to split HTTP and gRPC client endpoints onto separate listeners, the --client-crl-file Certificate Revocation List is not enforced on the...

Apache Tomcat: Apache Tomcat: Authentication bypass due to CLIENT_CERT soft fail misconfiguration

A flaw was found in Apache Tomcat and Apache Tomcat Native. When CLIENTCERT authentication is configured with "soft fail" disabled, the authentication process may not correctly fail in certain scenarios. This vulnerability could allow an attacker to bypass expected client certificate...

tomcat: Client certificate verification bypass due to virtual host mapping

A certificate validation flaw has been found in Apache Tomcat. omcat did not validate that the host name provided via the SNI extension was the same as the host name provided in the HTTP host header field. If Tomcat was configured with more than one virtual host and the TLS configuration for one ...