{"id":"AZL-91773","summary":"CVE-2026-50721 affecting package libreswan for versions less than 4.15-2","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":"2026-09-20T05:33:47Z","published":"2026-07-02T22:16:43Z","upstream":["CVE-2026-50721"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50721"}],"affected":[{"package":{"name":"libreswan","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/libreswan"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15-2"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-91773.json"}}],"schema_version":"1.9.0"}