{"id":"DEBIAN-CVE-2026-50721","details":"Libreswan, via the function RSA_authenticate_hash_signature_raw_rsa(), did not correctly verify the length of the authentication hash when the SIG payload of an IKEv1 packet was encoded using PKCS #1 RSA Encryption as per RFC 2313. A remote attacker can use a variation on the Bleichenbacher attack to forge the SIG payload when small public exponents are being used (e.g., e=3), which could lead to impersonation. Additionally, a remote attacker, by encoding a shorter than expected hash in the SIG payload, could trigger an assertion leading to denial-of-service. The daemon aborts and restarts; continued exploitation causes sustained denial of service. Remote code execution is not possible. X.509 certificate verifications of remote IKE peers are not affected.","modified":"2026-09-29T13:04:09.367024628Z","published":"2026-07-02T22:16:43.367Z","upstream":["CVE-2026-50721"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-50721"}],"affected":[{"package":{"name":"libreswan","ecosystem":"Debian:12","purl":"pkg:deb/debian/libreswan?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.10-2","4.10-2+deb12u1","4.11-1","4.12-1","4.12-2","4.12-3","4.14-1","4.14-1.1","4.15-1","5.0~rc2-1","5.0~rc2-2","5.2-1","5.2-2","5.2-2.1","5.2-2.2","5.2-2.3","5.2-2.4","5.2-2.5"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50721.json"}},{"package":{"name":"libreswan","ecosystem":"Debian:13","purl":"pkg:deb/debian/libreswan?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2-2.2","5.2-2.3","5.2-2.4","5.2-2.5"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50721.json"}},{"package":{"name":"libreswan","ecosystem":"Debian:14","purl":"pkg:deb/debian/libreswan?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.2-2.5"}]}],"versions":["5.2-2.2","5.2-2.3","5.2-2.4"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50721.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}