Unchecked Input for Loop Condition in strongSwan - CVE-2026-78129

Vulnerability identifier: #VU151589

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-78129

CWE-ID: CWE-606

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to missing bounds validation of PKCS#5 parameters in the PKCS#5 implementation in libstrongswan when processing an encrypted PKCS#7 container received via an IKEv1 certificate payload. A remote attacker can send a crafted encrypted PKCS#7 container to cause a denial of service.

Remote exploitation requires the pkcs7 plugin to be loaded and IKEv1 to be accepted.

strongSwan
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
Debian Linux
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Package Hub 15
Basesystem Module
openSUSE Leap
Ubuntu
strongswan-doc
strongswan-libs0
strongswan-hmac
strongswan-libs0-debuginfo
strongswan
strongswan-ipsec
strongswan-ipsec-debuginfo
strongswan-debugsource
strongswan-debuginfo
strongswan-mysql-debuginfo
strongswan-sqlite
strongswan-nm
strongswan-sqlite-debuginfo
strongswan-nm-debuginfo
strongswan-mysql
strongswan (Ubuntu package)
strongswan (Debian package)

Install security update from vendor's website.

strongSwan - update to 6.1.0
strongswan-doc - addressed in versions 5.1.3-26.43.2, 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-libs0 - addressed in versions 5.1.3-26.43.2, 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-hmac - addressed in versions 5.1.3-26.43.2, 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-libs0-debuginfo - addressed in versions 5.1.3-26.43.2, 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan - addressed in versions 5.1.3-26.43.2, 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-ipsec - addressed in versions 5.1.3-26.43.2, 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-ipsec-debuginfo - addressed in versions 5.1.3-26.43.2, 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-debugsource - addressed in versions 5.1.3-26.43.2, 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-debuginfo - addressed in versions 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-mysql-debuginfo - addressed in versions 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2
strongswan-sqlite - addressed in versions 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2
strongswan-nm - addressed in versions 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-sqlite-debuginfo - addressed in versions 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2
strongswan-nm-debuginfo - addressed in versions 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2, 5.9.14-150700.3.21.2
strongswan-mysql - addressed in versions 5.9.11-150400.19.40.2, 5.9.11-150500.5.28.2, 5.9.12-150600.3.23.2
strongswan (Ubuntu package) - addressed in versions 5.9.5-2ubuntu2.8, 5.9.13-2ubuntu4.24.04.5, 6.0.4-1ubuntu3.2
strongswan (Debian package) - update to 6.0.1-6+deb13u7

• https://www.strongswan.org/blog/2026/09/07/strongswan-vulnerability-(cve-2026-78129).html

• Multiple vulnerabilities in strongSwan
• Debian update for strongswan
• SUSE update for strongswan
• SUSE update for strongswan
• SUSE update for strongswan
• SUSE update for strongswan
• Ubuntu update for strongswan
• SUSE update for strongswan