CVE-2026-50722

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.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://libreswan.org/security/CVE-2026-50721/CVE-2026-50721.txt	Vendor Advisory Mailing List
https://libreswan.org/security/CVE-2026-50722/	Vendor Advisory
https://libreswan.org/security/CVE-2026-50722/CVE-2026-50722.txt	Vendor Advisory
https://www.rfc-editor.org/rfc/rfc8017	Technical Description

Configurations

Configuration 1 (hide)

cpe:2.3:a:libreswan:libreswan:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-07-02 22:16

Updated : 2026-07-09 15:47

NVD link : CVE-2026-50722

Mitre link : CVE-2026-50722

CVE.ORG link : CVE-2026-50722

JSON object : View

Products Affected

libreswan

libreswan

CWE

CWE-347

Improper Verification of Cryptographic Signature

CWE-617

Reachable Assertion

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