CVE-2026-62243
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-62243 is a high-severity Improper Validation of Certificate with Host Mismatch (CWE-297) vulnerability. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Adversary-in-the-Middle (T1557); ranked at the 4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SC-23 (Session Authenticity) and SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-64271
Vulnerability Data
Netty (io.netty:netty-handler) versions from 4.2.0.Final through 4.2.16.Final and versions through 4.1.136.Final disable TLS hostname verification on the SslProvider.OPENSSL client path when a plain (non-extended) X509TrustManager is used and Unsafe-based trust-manager wrapping is unavailable (Java 25+). In this configuration the OpenSSL…
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client does not perform hostname verification, allowing a man-in-the-middle attacker to present a certificate issued for a different hostname that is accepted without validation. Fixed in 4.2.17.Final and 4.1.137.Final.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V17.2.8
Mitigating Controls (NIST 800-53 r5) AI
Protecting session authenticity structurally requires proper certificate validation to bind the presented certificate to the intended host.
Requiring confidentiality and integrity of transmitted data necessitates correct TLS certificate validation with host-name checking.
Security engineering principles require correct implementation of certificate validation (including hostname matching) when cryptography is used.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Server/service authentication via certificates directly requires correct host validation.
Protecting data-in-transit integrity depends on proper certificate validation to prevent MITM.
Secure development practices include coding correct certificate validation logic.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Network security controls include certificate validation and host-name verification to prevent man-in-the-middle attacks.
Security of network services requires proper TLS configuration and certificate validation for service endpoints.
A.8.24 mandates proper use of cryptography (algorithms, key management, certificates for protection) but does not address or stop exploitation of a certificate-hostname validation flaw in the product's TLS handshake logic
Application security requirements include secure communication and certificate validation for external services.