Upstream information

CVE-2026-50721 at MITRE

Description

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.

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having important severity.

CVSS v3 Scores
CVSS detail CNA (d42dc95b-23f1-4e06-9076-20753a0fb0df) National Vulnerability Database
Base Score 8.1 5.9
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network Network
Attack Complexity High High
Privileges Required None None
User Interaction None None
Scope Unchanged Unchanged
Confidentiality Impact High None
Integrity Impact High None
Availability Impact High High
CVSSv3 Version 3.1 3.1
No SUSE Bugzilla entries cross referenced.

SUSE Security Advisories:

List of released packages

Product(s) Fixed package version(s) References
SUSE Liberty Linux 10
  • libreswan >= 5.3.2-1.el10_2
  • libreswan-minimal >= 5.3.2-1.el10_2
 Patchnames:
RHSA-2026:46398
SUSE Liberty Linux 8
  • libreswan >= 4.12-2.el8_10.6
 Patchnames:
RHSA-2026:46396
SUSE Liberty Linux 9
  • libreswan >= 4.15-10.el9_8
 Patchnames:
RHSA-2026:46397

SUSE Timeline for this CVE

CVE page created: Mon Jul 27 14:48:24 2026
CVE page last modified: Mon Jul 27 20:33:16 2026