CVE-2026-42790
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 validat
वीकनेस
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 validat
प्रभावित प्रोडक्ट
- erlang erlang\/otp
संदर्भ
- https://cna.erlef.org/cves/CVE-2026-42790.html
- https://github.com/erlang/otp/commit/0769050c69d73762672b0db1347b6993a5b31759
- https://github.com/erlang/otp/commit/21abed64eb2026b5f82f432709e4e932f9be389a
- https://github.com/erlang/otp/commit/fb67c6d1836f51105a96d8b769e71e4215a79457
- https://github.com/erlang/otp/security/advisories/GHSA-22cw-4ph4-6447
- https://osv.dev/vulnerability/EEF-CVE-2026-42790
हमलावर से पहले बग आप ढूँढें।
GitHub से साइन इन करें और एक मिनट से भी कम में अपना पहला ऑडिट चलाएँ। फ़्री प्लान के लिए क्रेडिट कार्ड की ज़रूरत नहीं।