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Libreswan

DEVOPS
Velocity5.0

IPsec VPN implementation for Linux and BSD supporting IKEv1 and IKEv2

libreswan.org ↗

Libreswan patches four CVEs on two lines, two of them credited to Claude and Ada Logics.

ipsecvpnsecurity-fixespost-quantum cryptoikev2
◆Current state
Libreswan is an IPsec VPN implementation for Linux and the BSDs. On October 5 it released 5.4.1 and 5.3.3 together: 5.4.1 fixes three CVEs (null-pointer crashes on unexpected EAP and empty PKCS7 payloads, and a use-after-free on EOF in IKE over TCP), and 5.3.3 fixes the same three plus a FIPS certificate-leak denial of service. v5.4 in August remains the latest feature release, adding ML-KEM 768 post-quantum key exchange via RFC 9370.
◆Where it's heading
Security response dominates the release history: 5.3.1, 5.3.2, 5.3.3 and 5.4.1 are all CVE releases, with 5.4 the one feature release among them. Recent CVEs credit AI-assisted audits, so the find rate may stay high while that tooling runs over the codebase.
◆Prediction
Expect further point releases on both the 5.3 and 5.4 lines while 5.3 is still maintained. The entries do not show when a 5.5 feature release is due.

◆Recent moves

  1. 1mo ago

    5.4.1 Security Release addresses three CVEs

    Three CVEs fixed on the current line, two of them credited to Claude and Ada Logics. It follows the ML-KEM feature release with the same security-first rhythm as the 5.3 patches.

    View source ↗
  2. 1mo ago

    5.3.3 Security Release addresses four CVEs

    The 5.3 maintenance line gets the same fixes plus a FIPS certificate-leak denial of service. Libreswan is still backporting to the previous minor, so users who have not moved to 5.4 are covered.

    View source ↗
  3. 2mo ago

    5.4: ML-KEM 768 and RFC 9370 multiple key exchanges for IKEv2

    ⚡ SPARK

    After two releases of pure CVE response, v5.4 is where Libreswan adds capability: post-quantum key exchange in IKEv2, built on a complete RFC 9370 implementation rather than bolted on. The maintenance half of the release — host-to-host and on-demand fixes on FreeBSD, NetBSD and OpenBSD, proposal parser updates, and a large logging cleanup — reflects the same operator-facing grind visible in earlier releases.

    View source ↗
  4. 3mo ago

    5.3.2: FIPS-mode daemon crash from malformed X.509 certificates

    A single-CVE release for an assertion failure that crashes pluto in FIPS mode when it parses a badly formatted X.509 certificate, repeatable into a denial of service. Notable for how it was found: the project ran an AI-assisted audit over its own codebase and this came out of it.

    View source ↗
  5. 4mo ago

    5.3.1: three CVEs and a newer-GCC compile fix

    Three CVEs closed in one release, plus a compile fix for newer GCC versions. Together with 5.3.2 a month later, it marks the stretch where Libreswan's release stream was entirely security response — the contrast that makes v5.4's feature work stand out.

    View source ↗
  6. 2y ago

    IKEv1 cryptosuite defaults tightened; systemd libxz dependency dropped

    Reworks IKEv1's default proposals — SHA2 added to AH, DH19 and DH31 into the IKE defaults, AEAD rejected when combined with non-NULL integrity — and drops the libxz dependency pulled in via libsystemd. Default-tightening on the legacy protocol, which is how IKEv1 gets maintained rather than extended.

    View source ↗