{"schemaVersion":3,"id":"CVE-2026-50722","aliases":["UBUNTU-CVE-2026-50722","DEBIAN-CVE-2026-50722"],"status":"published","duplicateOf":null,"title":null,"description":"Libreswan, via the function RSA_authenticate_hash_signature_pkcs1_1_5_rsa(), did not correctly verify the DER encoding of the ASN.1 digest when the IKEv2 AUTH payload was encoded using RSASSA-PKCS1-v1_5 (RFC 8017). A remote attacker can use a variation on the Bleichenbacher attack to forge the AUTH payload when small public exponents are used (e.g., e=3), leading to impersonation. Additionally, a remote attacker, by encoding a shorter than expected hash in the AUTH 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 the remote IKE peer are not affected.","dates":{"published":"2026-07-02T21:34:41.413Z","modified":"2026-07-07T17:02:06.722Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.5,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":5.9,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":5.6,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","score":5.9,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":5.6,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":5.9,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00346,"percentile":0.26754,"severity":"low","asOf":"2026-10-20T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-20T00:00:00.000Z","baselineScore":0.00346},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00346,"percentile":0.26754}],"last30":[{"date":"2026-09-20T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00432,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00346,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00346,"percentile":0.26754}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-347","name":"Improper Verification of Cryptographic Signature","description":"The product does not verify, or incorrectly verifies, the cryptographic signature for data.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/347.html"},{"id":"CWE-617","name":"Reachable Assertion","description":"The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/617.html"}],"affected":[{"vendor":"debian","product":"libreswan","name":"libreswan","label":"libreswan","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/libreswan","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null},{"text":"< 5.2-2.5","noFixRecorded":false,"fixedIn":null}],"versionsText":"All versions (No fix recorded) | < 5.2-2.5","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"libreswan","name":"libreswan","label":"libreswan","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/libreswan","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"libreswan","product":"libreswan","name":"libreswan","label":"libreswan","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 5.3.1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 5.3.1","eol":null,"hubHref":"/vendor/libreswan/libreswan"},{"vendor":"the libreswan project","product":"libreswan","name":"libreswan","label":"libreswan","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≤ 5.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"≤ 5.3","eol":null,"hubHref":"/vendor/the_libreswan_project/libreswan"}],"affectedCount":4,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://libreswan.org/security/CVE-2026-50722/CVE-2026-50722.txt","label":"libreswan.org/security/CVE-2026-50722/CVE-2026-50722.txt","hostname":"libreswan.org","tags":["Vendor Advisory","REPORT"]},{"url":"https://libreswan.org/security/CVE-2026-50722/","label":"libreswan.org/security/CVE-2026-50722/","hostname":"libreswan.org","tags":["Patch","REPORT","Vendor Advisory"]},{"url":"https://libreswan.org/security/CVE-2026-50721/CVE-2026-50721.txt","label":"libreswan.org/security/CVE-2026-50721/CVE-2026-50721.txt","hostname":"libreswan.org","tags":["Related","REPORT","Vendor Advisory","Mailing List"]},{"url":"https://www.rfc-editor.org/rfc/rfc8017","label":"www.rfc-editor.org/rfc/rfc8017","hostname":"www.rfc-editor.org","tags":["Technical Description","REPORT"]},{"url":"https://ubuntu.com/security/CVE-2026-50722","label":"ubuntu.com/security/CVE-2026-50722","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-50722","label":"www.cve.org/CVERecord?id=CVE-2026-50722","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-50722","label":"security-tracker.debian.org/tracker/CVE-2026-50722","hostname":"security-tracker.debian.org","tags":["Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50722","label":"nvd.nist.gov/vuln/detail/CVE-2026-50722","hostname":"nvd.nist.gov","tags":["Oval","Advisory"]}],"lineage":{"upstream":[],"downstream":["RHSA-2026:46396","RHSA-2026:46397","RHSA-2026:46398","RHSA-2026:46986","RHSA-2026:55449","RHSA-2026:57741","RHSA-2026:61258","RHSA-2026:61779","RHSA-2026:72287","RHSA-2026:82154","RHSA-2026:84887"],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-07-02T21:34:41.413Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-07-07T17:02:06.722Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":30,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T14:36:13.544Z","stale":false,"partial":false}}