{"id":"DEBIAN-CVE-2026-5501","details":"wolfSSL_X509_verify_cert in the OpenSSL compatibility layer accepts a certificate chain in which the leaf's signature is not checked, if the attacker supplies an untrusted intermediate with Basic Constraints `CA:FALSE` that is legitimately signed by a trusted root. An attacker who obtains any leaf certificate from a trusted CA (e.g. a free DV cert from Let's Encrypt) can forge a certificate for any subject name with any public key and arbitrary signature bytes, and the function returns `WOLFSSL_SUCCESS` / `X509_V_OK`. The native wolfSSL TLS handshake path (`ProcessPeerCerts`) is not susceptible and the issue is limited to applications using the OpenSSL compatibility API directly, which would include integrations of wolfSSL into nginx and haproxy.","modified":"2026-09-14T17:03:19.751644293Z","published":"2026-04-10T04:17:17.230Z","upstream":["CVE-2026-5501"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-5501"}],"affected":[{"package":{"name":"wolfssl","ecosystem":"Debian:12","purl":"pkg:deb/debian/wolfssl?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.5.4-2","5.5.4-2+deb12u1","5.5.4-2+deb12u2","5.5.4-2+deb12u3","5.5.4-2.1","5.6.4-1","5.6.4-2","5.6.6-1","5.6.6-1.1","5.6.6-1.2","5.6.6-1.3","5.6.6-1.3~exp1","5.7.0-0.1","5.7.0-0.2","5.7.0-0.3","5.7.2-0.1","5.7.2-0.2","5.7.2-0.3","5.7.2-0.4","5.8.2-1","5.8.2-1.1","5.8.2-1.2","5.8.4-1","5.9.0-0.1","5.9.0-0.2","5.9.1-0.1","5.9.2-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-5501.json"}},{"package":{"name":"wolfssl","ecosystem":"Debian:13","purl":"pkg:deb/debian/wolfssl?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.7.2-0.1","5.7.2-0.1+deb13u1","5.7.2-0.1+deb13u2","5.7.2-0.2","5.7.2-0.3","5.7.2-0.4","5.8.2-1","5.8.2-1.1","5.8.2-1.2","5.8.4-1","5.9.0-0.1","5.9.0-0.2","5.9.1-0.1","5.9.2-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-5501.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"}]}