{"id":"DEBIAN-CVE-2026-5503","details":"In TLSX_EchChangeSNI, the ctx-\u003eextensions branch set extensions unconditionally even when TLSX_Find returned NULL. This caused TLSX_UseSNI to attach the attacker-controlled publicName to the shared WOLFSSL_CTX when no inner SNI was configured. TLSX_EchRestoreSNI then failed to clean it up because its removal was gated on serverNameX != NULL. The inner ClientHello was sized before the pollution but written after it, causing TLSX_SNI_Write to memcpy 255 bytes past the allocation boundary.","modified":"2026-09-14T17:03:19.791679902Z","published":"2026-04-09T23:17:01.257Z","upstream":["CVE-2026-5503"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-5503"}],"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-2026-5503.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-2026-5503.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"}]}