CVE-2026-50721

{"id": "CVE-2026-50721", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-50721", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-06T18:12:17.199605Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.1, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.2}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 2.2}]}, "affected": [{"source": "d42dc95b-23f1-4e06-9076-20753a0fb0df", "affectedData": [{"repo": "https://github.com/libreswan/libreswan", "vendor": "The Libreswan Project", "product": "libreswan", "versions": [{"status": "affected", "version": "0", "versionType": "semver", "lessThanOrEqual": "5.3"}, {"status": "unaffected", "version": "5.3.1", "versionType": "semver"}], "packageName": "libreswan", "collectionURL": "https://github.com/libreswan/libreswan", "defaultStatus": "unaffected", "programRoutines": [{"name": "RSA_authenticate_hash_signature_raw_rsa"}]}]}], "published": "2026-07-02T22:16:43.367", "references": [{"url": "https://libreswan.org/security/CVE-2026-50721/", "tags": ["Vendor Advisory"], "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df"}, {"url": "https://libreswan.org/security/CVE-2026-50721/CVE-2026-50721.txt", "tags": ["Vendor Advisory"], "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df"}, {"url": "https://libreswan.org/security/CVE-2026-50722/CVE-2026-50722.txt", "tags": ["Vendor Advisory"], "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df"}, {"url": "https://www.rfc-editor.org/rfc/rfc2313", "tags": ["Technical Description"], "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df", "description": [{"lang": "en", "value": "CWE-347"}, {"lang": "en", "value": "CWE-617"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-07-09T15:46:40.770", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:libreswan:libreswan:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0D5C4D8F-3003-4ACA-A065-E03AEE680115", "versionEndExcluding": "5.3.1"}], "operator": "OR"}]}], "sourceIdentifier": "d42dc95b-23f1-4e06-9076-20753a0fb0df"}