Description
libcharon in strongSwan 5.9.7 through 6.0.7 mishandles behavioral workflow in the IKEv2 state machine. Because CREATE_CHILD_SA requests are mishandled, there can be an authentication bypass.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| strongSwan | strongSwan | 5.9.7 – < 6.1.0 | 6.1.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | strongswan | 6.1.0-1 | — |
| Debian 13 | strongswan | 6.0.1-6+deb13u7 | — |
| Debian 12 | strongswan | 5.9.8-5+deb12u6 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | strongswan | 6.0.4-1ubuntu3.2 | USN-8789-1 |
| Ubuntu 24.04 LTS | strongswan | 5.9.13-2ubuntu4.24.04.5 | USN-8789-1 |
| Ubuntu 22.04 LTS | strongswan | 5.9.5-2ubuntu2.8 | USN-8789-1 |
| Ubuntu 20.04 LTS | strongswan | No fix yet | — |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro 18.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro 16.04 LTS | strongswan | No fix yet | — |
| Ubuntu Pro 14.04 LTS | strongswan | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | strongswan | 5.9.14-150700.3.21.2 | SUSE-SU-2026:4115-1 |
| SLES 15 SP4 | strongswan | 5.9.11-150400.19.40.2 | SUSE-SU-2026:4146-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | strongswan | 6.0.6-160000.3.1 | SUSE-SU-2026:24199-1 |
| SLES for SAP 15 SP4 | strongswan | 5.9.11-150400.19.40.2 | SUSE-SU-2026:4146-1 |
| SLES 16.0 | strongswan | 6.0.6-160000.3.1 | SUSE-SU-2026:24199-1 |
| SLE HPC 15 SP4 | strongswan | 5.9.11-150400.19.40.2 | SUSE-SU-2026:4146-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | strongswan | 6.1.0-1.1 | openSUSE-SU-2026:11749-1 |
| openSUSE Leap 16.0 | strongswan | 6.0.6-160000.3.1 | openSUSE-SU-2026:22050-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | strongswan | 5.9.14-11 | — |
Advisories 7
- WID-SEC-2026-3230 strongSwan: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 9, 2026
- SUSE-SU-2026:24199-1 Security update for strongswan SUSE / openSUSE Security Updates · Oct 21, 2026
- openSUSE-SU-2026:22050-1 Security update for strongswan SUSE / openSUSE Security Updates · Oct 19, 2026
- USN-8789-1 strongswan vulnerabilities Ubuntu Security Notices (USN) · Sep 21, 2026
- SUSE-SU-2026:4146-1 Security update for strongswan SUSE / openSUSE Security Updates · Sep 15, 2026
- SUSE-SU-2026:4115-1 Security update for strongswan SUSE / openSUSE Security Updates · Sep 14, 2026
- openSUSE-SU-2026:11749-1 strongswan-6.1.0-1.1 on GA media SUSE / openSUSE Security Updates · Sep 11, 2026