An issue was discovered in OpenStack oslo.messaging 1.0.0 through 17.3.0. The oslo.messaging RabbitMQ driver does not perform TLS hostname verification when connecting to the message broker. When ssl_ca_file is configured, the driver enables certificate chain validation but does not pass the expected broker hostname into the underlying TLS stack. Any certificate signed by the deployment CA is accepted regardless of hostname, allowing an attacker who can intercept control-plane traffic to impersonate the RabbitMQ broker and perform a man-in-the-middle attack on RPC and notification traffic. All OpenStack services using oslo.messaging with RabbitMQ over TLS are affected.
A network man-in-the-middle between nats-sync and the BOSH director can steal the director credentials (Basic auth header or UAA client secret) and can tamper with the VM list that is written into the NATS authorization file. Stolen credentials grant administrative director access. UsersSync#bosh_api_response_body builds a Net::HTTP client with verify_mode = OpenSSL::SSL::VERIFY_NONE for every director call (/info, /deployments, /deployments/<name>/vms).
Affected versions:
- BOSH: all versions prior to v282.1.9 (inclusive); fixed in v282.1.9 or later
Apache Airflow's EmailOperator and the underlying `airflow.utils.email` helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used `[email] smtp_starttls=True` without `[email] smtp_ssl`. An attacker positioned between the worker and the configured SMTP server (network MITM — typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker's trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded.
This CVE covers the **core apache-airflow side** of the same root cause already covered for the SMTP provider by `CVE-2026-41016` (published 2026-04-27, covering `apache-airflow-providers-smtp`). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade `apache-airflow` to 3.2.2 or later to cover the core-side path through `airflow.utils.email`. Affects deployments configured with `smtp_starttls=True` and `smtp_ssl=False` where the SMTP relay is reachable across a less-trusted network segment than the worker.
Users are advised to upgrade to `apache-airflow` 3.2.2 or later.
CVE-2026-47074 is a high-severity vulnerability in the ex-aws ex_aws_sns library affecting versions from 2.0.1 up to but not including 2.3.5. The issue involves improper certificate validation in the SNS message verification process, where the SigningCertURL is not properly checked to ensure it uses HTTPS or belongs to an AWS-owned domain. This flaw allows attackers to spoof SNS message signatures by supplying a malicious SigningCertURL, potentially causing forged SNS messages to be accepted as valid. A patch is available, and since this is a cloud service, the vendor typically manages remediation server-side. No known exploits are reported in the wild at this time.
Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_cert and public_key modules) allows a DNS nameConstraints bypass via subject CommonName fallback in TLS hostname verification.
Two flaws combine to allow a subordinate CA whose DNS nameConstraints are restricted (e.g. permitted;DNS:allowed.example.com) to issue a leaf certificate that an OTP TLS client accepts as a valid identity for an out-of-scope hostname (e.g. victim.example.com):
First, pubkey_cert:validate_names/6 in lib/public_key/src/pubkey_cert.erl only checks SAN DNS entries against nameConstraints. Per RFC 5280, a permitted DNS subtree only restricts certificates that contain a DNS-typed name. A leaf with no subjectAltName therefore trivially satisfies any permitted;DNS:... constraint regardless of its subject commonName.
Second, public_key:pkix_verify_hostname/3 in lib/public_key/src/public_key.erl falls back to the subject commonName when no subjectAltName is present, extracting id-at-commonName attributes as presented IDs and matching them against the reference hostname. The strict pkix_verify_hostname_match_fun(https) matcher does not suppress this fallback.
The result is that path validation accepts a CN-only leaf under a DNS-constrained intermediate (no SAN means the nameConstraints are not triggered), and hostname verification then accepts it via the CN fallback. The bypass is reachable from stock ssl:connect with verify_peer, a trusted CA, SNI, and the canonical strict https hostname matcher.
This issue affects OTP from OTP 19.3 before OTP 29.0.1, OTP 28.5.0.1, OTP 27.3.4.12 and OTP 26.2.5.21, corresponding to public_key from 1.4 before 1.21.1, 1.20.3.1, 1.17.1.3 and 1.15.1.7.
Improper Certificate Validation vulnerability in Erlang OTP public_key (pubkey_ocsp module) allows forged OCSP responses signed with an expired responder certificate to be accepted as valid.
OCSP response verification in pubkey_ocsp:verify_response/5 and pubkey_ocsp:is_authorized_responder/3 in lib/public_key/src/pubkey_ocsp.erl does not check the validity period (notBefore/notAfter) of the OCSP responder certificate. An attacker who has obtained the private key of an expired CA-designated OCSP responder certificate can forge OCSP responses that Erlang/OTP accepts as valid.
This affects TLS clients using OCSP stapling via the ssl application: a malicious or compromised server can present a revoked TLS certificate together with a forged OCSP response signed by an expired responder key, and the client will accept the revoked certificate as valid. It also affects applications calling public_key:pkix_ocsp_validate/5 directly, where the impact depends on the use case — server-side client certificate validation using this API may allow authentication bypass with a revoked client certificate.
This issue affects OTP from OTP 27.0 before OTP 29.0.1, OTP 28.5.0.1 and OTP 27.3.4.12, corresponding to public_key from 1.16 before 1.21.1, 1.20.3.1 and 1.17.1.3.
Improper Following of a Certificate's Chain of Trust vulnerability in Erlang OTP public_key (pubkey_cert module) allows a non-CA certificate to be accepted as an intermediate issuer, enabling certificate chain forgery.
In lib/public_key/src/pubkey_cert.erl, pubkey_cert:validate_extensions/7 contains two flaws that together allow a certificate with basicConstraints cA:false and no keyUsage extension to be used as an intermediate issuer in a chain passed to public_key:pkix_path_validation/3: the cA:false clause recurses into the remaining extensions without rejecting the certificate when it is in issuer position, and the keyUsage check only fires when the extension is present, so a certificate lacking keyUsage entirely bypasses the keyCertSign enforcement.
Any party holding an end-entity certificate with basicConstraints cA:false and no keyUsage extension, issued by any CA in the victim's trust store, can use that certificate's private key to sign forged leaf certificates for arbitrary identities. public_key:pkix_path_validation/3 accepts the resulting chain, and by extension every TLS or mTLS endpoint built on the OTP ssl application that relies on the default verifier is affected, including server identity verification on the client side and client certificate verification on mTLS servers.
This issue affects OTP from OTP 17.0 before OTP 27.3.4.19, OTP 28.5.0.8, and OTP 29.1.2, corresponding to public_key from 0.22 before 1.17.1.7, 1.20.3.6, and 1.21.8. Whether OTP before OTP 17.0, corresponding to public_key before 0.22, is affected is unknown.
CVE-2026-42013 is a vulnerability in the GnuTLS library where an oversized Subject Alternative Name (SAN) in a certificate causes the validation process to incorrectly fall back to checking the Common Name (CN) field. This flaw can allow remote attackers to bypass proper certificate validation, potentially enabling spoofing or man-in-the-middle attacks. The issue affects certain versions of GnuTLS in Red Hat Enterprise Linux 7 Extended Lifecycle Support. Red Hat has released an official security update that addresses this vulnerability.
A vulnerability in GnuTLS allows a remote attacker to bypass certificate validation by presenting a specially crafted certificate containing URI or SRV Subject Alternative Names (SANs). This causes the validation process to incorrectly fallback to checking DNS hostnames against the Common Name (CN), potentially enabling spoofing of legitimate services or interception of sensitive data. The issue affects specific versions of GnuTLS and has a CVSS score of 7.1, indicating high severity. Red Hat has released security updates addressing this and related vulnerabilities in GnuTLS for their Extended Life Cycle Support 7 product line.
The OpenTelemetry.Exporter.Instana exports telemetry to Instana backend. Prior to 1.1.0, the OpenTelemetry.Exporter.Instana NuGet package does not validate HTTPS/TLS certificates are valid when sending telemetry to a configured Instana back-end when a proxy is configured using the INSTANA_ENDPOINT_PROXY environment variable. If a network attacker can Man-in-the-Middle (MitM) the proxy connection, all OpenTelemetry telemetry data and the Instana API key are exposed to the attacker. This vulnerability is fixed in 1.1.0.
CVE-2026-44900 is a high-severity vulnerability in oviva-ag's epa4all-client Java client prior to version 1.2.1. The vulnerability arises because the method SignedPublicKeysTrustValidatorImpl.isTrusted() fails to verify the result of the ECDSA signature check, effectively trusting any structurally valid signature. Although the method performs certificate chain validation and OCSP checks, it does not confirm that the signature actually matches, leading to improper certificate validation. This flaw could allow an attacker to bypass signature verification, impacting confidentiality and integrity. The issue is fixed in version 1.2.1.
epa4all-client is the Java Client for epa4all / ePA 3.0 in the Telematik Infrastruktur. Prior to 1.2.2, an attacker on the network path between the ePA service and the Konnektor can present any TLS certificate (self-signed, expired, wrong CN) and intercept all SOAP traffic. This includes patient identifiers (KVNR), SMC-B card operations (authentication, signing), document content, and credential exchanges. This vulnerability is fixed in 1.2.2.
For untrusted certificates that contain the "Authority Information Access - caIssuers URI" extension, Szafir SDK will automatically download the parent CA certificate from the specified URL and will import it to its trust store as a "nonqualified" certificate. In such a case, Szafir SDK returns a success status code of 0 ("Positively verified") upon successful cryptographic verification and a certificate status of "nonqualified".
For other types of untrusted certificates, Szafir SDK returns a success status code of 0 ("Positively verified") upon successful cryptographic verification and a certificate status of "nondetermined".
This may lead integrating applications to incorrectly treat the digital signature as valid despite an untrusted certificate chain. This flaw enables authentication bypass and user impersonation:
(1) in use-cases other than qualified certificate authentication, or
(2) if the qualified certificate authentication use-case is not correctly implemented by the integrating application.
This issue was fixed in version 1.8.463.2.
Sunshine is a self-hosted game stream host for Moonlight. In versions prior to 2026.516.143833, the client-certificate authentication can be bypassed because of how OpenSSL verification results are handled. In src/crypto.cpp, the custom verify callback treats X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY, X509_V_ERR_CERT_NOT_YET_VALID, and X509_V_ERR_CERT_HAS_EXPIRED as success. This can allow an untrusted certificate to pass authentication and access protected HTTPS endpoints. This issue has been fixed in version 2026.516.143833.
CVE-2026-8992 is a high-severity vulnerability in Ivanti Secure Access Client prior to version 22.8R6. It involves improper certificate validation (CWE-295) that could allow a remote unauthenticated attacker to execute arbitrary code. The vulnerability has a CVSS score of 8.8, indicating a critical impact on confidentiality, integrity, and availability. No official patch or remediation guidance has been confirmed yet from the vendor. There are no known exploits in the wild at this time.
Dell PowerFlex Manager, version(s) <=4.6.2, contain(s) an Improper Certificate Validation vulnerability. An unauthenticated attacker with adjacent network access could potentially exploit this vulnerability, leading to Information tampering.
Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked.
Dell Live Optics Windows and Personal Edition collectors have an improper certificate validation vulnerability (CWE-295). This flaw could allow a remote unauthenticated attacker to compromise confidentiality and integrity by exploiting the certificate validation weakness. The vulnerability has a CVSS 3.1 base score of 6.8, indicating a medium severity level. No official patch or remediation guidance is currently provided by the vendor. There are no known exploits in the wild at this time.
Gitsign is a keyless Sigstore to signing tool for Git commits with your a GitHub / OIDC identity. Prior to 0.16.0, gitsign verify and gitsign verify-tag re-encode commit/tag objects through go-git's EncodeWithoutSignature before checking the signature, instead of verifying against the raw git object bytes. For malformed objects with duplicate tree headers, git-core and go-git parse different trees: git-core uses the first, go-git uses the second. A signature crafted over the go-git-normalized form (second tree) passes gitsign verify while git-core resolves the commit to a completely different tree. This breaks the invariant that a verified signature, the commit semantics git-core presents to users, and the object hash logged in Rekor all refer to the same content. This vulnerability is fixed in 0.16.0.