Hi,

The following vulnerabilities were published for libreswan.

CVE-2026-12413[0]:
| An invalidly formatted IKEv2 fragment causes the Libreswan pluto
| daemon to crash and restart. Continued exploitation would cause a
| denial of service. The function reassemble_v2_incoming_fragments()
| would ignore unknown outer payloads but still store these in a fixed
| size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the
| assertion PASSERT(logger, md->digest_roof < elemsof(md->digest))
| causes the daemon to abort. No remote code execution is possible.
| Any configuration that allows IKEv2 connections that do not set
| fragmentation=no are vulnerable. IKEv1 is not affected.


CVE-2026-50721[1]:
| 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.


CVE-2026-50722[2]:
| 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.


If you fix the vulnerabilities please also make sure to include the
CVE (Common Vulnerabilities & Exposures) ids in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-12413
https://www.cve.org/CVERecord?id=CVE-2026-12413
https://libreswan.org/security/CVE-2026-12413/CVE-2026-12413.txt
[1] https://security-tracker.debian.org/tracker/CVE-2026-50721
https://www.cve.org/CVERecord?id=CVE-2026-50721
https://libreswan.org/security/CVE-2026-50721/CVE-2026-50721.txt
[2] https://security-tracker.debian.org/tracker/CVE-2026-50722
https://www.cve.org/CVERecord?id=CVE-2026-50722
https://libreswan.org/security/CVE-2026-50722/CVE-2026-50722.txt

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore

Dear maintainer,

I've prepared an NMU for libreswan (versioned as 5.2-2.5) and uploaded
it to DELAYED/2. Please feel free to tell me if I should cancel it.

cu
Adrian

We believe that the bug you reported is fixed in the latest version of
libreswan, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1141390@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Adrian Bunk <bunk@debian.org> (supplier of updated libreswan package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Thu, 06 Aug 2026 16:04:55 +0300
Source: libreswan
Architecture: source
Version: 5.2-2.5
Distribution: unstable
Urgency: medium
Maintainer: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Changed-By: Adrian Bunk <bunk@debian.org>
Closes: 1133535 1141390 1143067
Changes:
 libreswan (5.2-2.5) unstable; urgency=medium
 .
   * Non-maintainer upload.
   * Backport upstream fix for FTBFS with GCC 16. (Closes: #1133535)
   * CVE-2026-50721: IKEv1 Denial of Service via RSA-SHA1
     authentication payload
   * CVE-2026-50722: IKEv2 Denial of Service via RSA-SHA1
     authentication payload
   * CVE-2026-12413: IKEv2 Denial of Service via malformed fragmentation
   * (Closes: #1141390)
   * CVE-2026-14957: FIPS mode reachable assertion (Closes: #1143067)
Checksums-Sha1:
 084a62211c96f02316cc00f5b6d190d1018b2ebb 2640 libreswan_5.2-2.5.dsc
 0721c3a88f316023bbe7308c4d88e16509355a05 19076 libreswan_5.2-2.5.debian.tar.xz
Checksums-Sha256:
 0dce4f1152426e3e7c0a6fb73286e53c118e90db49fd8ba321eebce9baccd6b5 2640 libreswan_5.2-2.5.dsc
 69c644a8530d5cd396496688b7347b0c7333d7a8d0baff072cb3990a4a0cc84f 19076 libreswan_5.2-2.5.debian.tar.xz
Files:
 3e1728206c72c7f9cea54de57515eda9 2640 net optional libreswan_5.2-2.5.dsc
 eeb668a51210b152929a779d071ed29f 19076 net optional libreswan_5.2-2.5.debian.tar.xz
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