CVE Feed

    Dashboard / CVE / CVE-2026-27138

    CVE-2026-27138

    Certificate verification can panic when a certificate in the chain has an empty DNS name and another certificate in the chain has excluded name constraints. This can crash programs that are either directly verifying X.509 certificate chains, or those that use TLS.

    Published:Mar 6, 2026
    Last Modified:Apr 21, 2026
    EPS:Mar 6, 2026
    EPSS Score:0.00021
    CVSS Score:5.9

    Affected Products

    Vendor
    Go Standard Library
    Product
    Crypto Tls
    Vendor
    Golang
    Product
    Go

    Exploits

    No exploit reference

    Common Weakness Enumeration

    CWE-295 Improper Certificate Validation

    Related CVEs

    CVE-2026-56862 (CVSS 7.5) — Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a hands…
    CVE-2026-42505 (CVSS 5.3) — Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a dis…
    CVE-2026-32283 (CVSS 7.5) — If one side of the TLS connection sends multiple key update messages post-handshake in a single record, the co…
    CVE-2026-27137 (CVSS 7.5) — When verifying a certificate chain which contains a certificate containing multiple email address constraints …
    CVE-2025-68121 (CVSS 10) — During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated …
    CVE-2025-61730 (CVSS 5.3) — During the TLS 1.3 handshake if multiple messages are sent in records that span encryption level boundaries (f…
    CVE-2025-61727 (CVSS 6.5) — An excluded subdomain constraint in a certificate chain does not restrict the usage of wildcard SANs in the le…
    CVE-2025-61729 (CVSS 7.5) — Within HostnameError.Error(), when constructing an error string, there is no limit to the number of hosts that…
    CVE-2023-39322 (CVSS 7.5) — QUIC connections do not set an upper bound on the amount of data buffered when reading post-handshake messages…

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High