RockyLinux 8 : libreswan (RLSA-2026:46396)

The remote RockyLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:46396 advisory. librenswan: IKEv1 Denial of Service via RSA-SHA1 PKCS1 Version 1.5 Encrypted authentication payload CVE-2026-50721 librenswan: IKEv2 Denial of Service v...

SUSE CVE-2026-50721

Libreswan, via the function RSAauthenticatehashsignaturerawrsa, 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 for...

librenswan: IKEv1 Denial of Service via RSA-SHA1 (PKCS#1 Version 1.5 Encrypted) authentication payload

A flaw was found in Libreswan's implementation of IKEv1 authentication via raw RSA signatures. When processing an IKEv1 packet using PKCS 1 v1.5 RSA encryption, the RSAauthenticatehashsignaturerawrsa function fails to properly validate the length of the authentication hash. A remote,...

Important: Red Hat Security Advisory: libreswan security update

An update for libreswan is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System CVSS base score, which gives a detailed severity rating, is available for each vulnerability from...

EUVD-2026-41439

An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemblev2incomingfragments would ignore unknown outer payloads but still store these in a fixed size array msgdigest.digestPAYLIMIT...

EUVD-2026-41441

Libreswan, via the function RSAauthenticatehashsignaturerawrsa, 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 for...

CVE-2026-50721

Libreswan, via the function RSAauthenticatehashsignaturerawrsa, 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 for...

CVE-2026-50721

Libreswan, via the function RSAauthenticatehashsignaturerawrsa, 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 for...

CVE-2026-12413

An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemblev2incomingfragments would ignore unknown outer payloads but still store these in a fixed size array msgdigest.digestPAYLIMIT...

CVE-2026-50721

Libreswan, via the function RSAauthenticatehashsignaturerawrsa, 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 for...

CVE-2026-50721 IKEv1 Denial of Service via RSA-SHA1 (PKCS#1 Version 1.5 Encrypted) authentication payload

Libreswan, via the function RSAauthenticatehashsignaturerawrsa, 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 for...

CVE-2026-50721

Libreswan, via the function RSAauthenticatehashsignaturerawrsa, 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 for...

CVE-2026-50721

Libreswan, via the function RSAauthenticatehashsignaturerawrsa, 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 for...

CVE-2026-50721

CVE-2026-50721 concerns Libreswan where the function RSA_authenticate_hash_signature_raw_rsa() does not properly verify the authentication hash length when the SIG payload of an IKEv1 packet is encoded using PKCS#1 RSA Encryption per RFC 2313. This enables a remote attacker to leverage a Bleichen...

PT-2026-55315

Name of the Vulnerable Software and Affected Versions Libreswan affected versions not specified Description Libreswan fails to correctly verify the authentication hash length when the SIG payload of an IKEv1 packet is encoded using PKCS 1 RSA Encryption. This occurs within the RSA authenticate ha...

Exploit for Improper Authentication in Checkpoint Gaia_Os

markdown CVE-2026-50751 - Check Point IKEv1 Authentication Byp...

Critical Check Point VPN Zero-Day Exploited in the Wild (CVE-2026-50751)

Overview On June 8, 2026, Check Point published a security advisory for CVE-2026-50751, a critical authentication bypass vulnerability affecting Check Point Remote Access VPN, Mobile Access, and Spark Firewall products. The vulnerability affects deployments configured to use the deprecated IKEv1...

Critical Check Point VPN Flaw Exploited to Bypass Passwords in IKEv1 Setups

Check Point has warned of active exploitation of a critical vulnerability impacting Remote Access VPN and Mobile Access deployments that are configured to use the deprecated IKEv1 key exchange protocol. The vulnerability, tracked as CVE-2026-50751 CVSS score: 9.3, is a case of a logic flow weakne...

CVE-2026-50752

A weakness in the certificate validation logic of the deprecated IKEv1 key exchange may allow an unauthenticated attacker positioned as a man-in-the-middle to bypass certificate validation in VPN site-to-site connections that use certificate-based authentication. Successful exploitation could all...

CLSA-2025-1757947429 libreswan: Fix of CVE-2023-38711

CVE-2023-38711: fix a NULL pointer dereference in IKEv1 Quick Mode with IDIPV4ADDR/IDIPV6ADDR that causes a crash and restart of the pluto daemon when it receives an IDcr payload with IDFQDN...