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Red Hat Security Advisory

RHSA-2026:57741

libreswan security update

Released 2026-08-20 · Red Hat rating Important · View on Red Hat →

Fixed in

Fixes 4 records

TI-2026-37395 CVE-2026-50722 · GHSA-h4cv-5vw8-2p6m

IKEv2 Denial of Service via RSA-SHA1 (PKCS#1 RSASSA-PKCS1-v1_5) authentication payload

Priority MEDIUM 41

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).

CVSS 3.1HIGH 8.1 Network No auth No interaction EPSS 0.00346 Published 2026-07-02 Partial fix · 5.3.1 CWE-347
TI-2026-37394 CVE-2026-50721 · GHSA-93pj-2pmf-2x7p

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

Priority MEDIUM 41

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 pe…

CVSS 3.1HIGH 8.1 Network No auth No interaction EPSS 0.00386 Published 2026-07-02 Partial fix · 5.3.1 CWE-347
TI-2026-10657 CVE-2026-12413 · GHSA-vj68-68x2-jwjq

IKEv2 Denial of Service via malformed fragmentation

Priority MEDIUM 40

An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart.

CVSS 3.1HIGH 7.5 Network No auth No interaction EPSS 0.00598 Published 2026-07-02 Partial fix · 5.3.1 CWE-193
TI-2026-12595 CVE-2026-14957 · GHSA-x2hf-3rgr-r89x

FIPS mode assertion failure via malicious CERT payload

Priority LOW 39

In FIPS mode, Libreswan's add_decoded_cert() function calls CERT_ExtractPublicKey() and asserts that the result is not NULL.

CVSS 3.1HIGH 7.5 Network No auth No interaction EPSS 0.00468 Published 2026-09-02 Partial fix · 5.3.2 CWE-252