Description
In strongSwan before 5.9.5, a malicious responder can send an EAP-Success message too early without actually authenticating the client and (in the case of EAP methods with mutual authentication and EAP-only authentication for IKEv2) even without server authentication.
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 | 5.9.5-1 | — |
| Debian 13 | strongswan | 5.9.5-1 | — |
| Debian 12 | strongswan | 5.9.5-1 | — |
| Debian 11 | strongswan | 5.9.1-1+deb11u2 | DSA-5056-1 |
| Debian 10 | strongswan | 5.7.2-1+deb10u2 | DSA-5056-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 9 | strongswan | 5.5.1-4+deb9u6 | DLA-2909-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | strongswan | 5.9.4-1ubuntu4 | — |
| Ubuntu 20.04 LTS | strongswan | 5.8.2-1ubuntu3.4 | USN-5250-1 |
| Ubuntu 18.04 LTS | strongswan | 5.6.2-1ubuntu2.8 | USN-5250-1 |
Show 8 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 20.04 LTS | strongswan | 5.8.2-1ubuntu3.fips.3.4.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | strongswan | 5.6.2-1ubuntu2.fips.2.8.1 | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | strongswan | 5.3.5-1ubuntu3.fips.3.8.3 | — |
| Ubuntu Pro 16.04 LTS | strongswan | 5.3.5-1ubuntu3.8+esm2 | USN-5250-2 |
| Ubuntu Pro 14.04 LTS | strongswan | 5.1.2-0ubuntu2.11+esm2 | USN-5250-2 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SLES 15 SP2 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SLES 15 SP1 | strongswan | 5.8.2-4.17.1 | SUSE-SU-2022:0211-1 |
| SLES 15 | strongswan | 5.8.2-4.17.1 | SUSE-SU-2022:0211-1 |
| SLES 12 SP5 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
Show 25 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SLES 12 SP3 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SLES 12 SP2 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SLES 11 SP4 | strongswan | 4.4.0-6.36.12.1 | SUSE-SU-2022:14887-1 |
| SLES for SAP 15 SP2 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SLES for SAP 15 SP1 | strongswan | 5.8.2-4.17.1 | SUSE-SU-2022:0211-1 |
| SLES for SAP 15 | strongswan | 5.8.2-4.17.1 | SUSE-SU-2022:0211-1 |
| SLES for SAP 12 SP5 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SLES for SAP 12 SP4 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SLES for SAP 12 SP3 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SLE Real Time 15 SP2 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SLE HPC 15 SP2 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SLE HPC 15 SP1 | strongswan | 5.8.2-4.17.1 | SUSE-SU-2022:0211-1 |
| SLE HPC 15 | strongswan | 5.8.2-4.17.1 | SUSE-SU-2022:0211-1 |
| SUSE OpenStack Cloud Crowbar 9 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SUSE OpenStack Cloud Crowbar 8 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SUSE OpenStack Cloud 9 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SUSE OpenStack Cloud 8 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SUSE Manager Server 4.1 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SUSE Manager Retail Branch Server 4.1 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SUSE Manager Proxy 4.1 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | strongswan | 4.4.0-6.36.12.1 | SUSE-SU-2022:14887-1 |
| SUSE HPE Helion OpenStack 8 | strongswan | 5.1.3-26.20.1 | SUSE-SU-2022:0202-1 |
| SUSE Enterprise Storage 7 | strongswan | 5.8.2-11.24.1 | SUSE-SU-2022:0492-1 |
| SUSE Enterprise Storage 6 | strongswan | 5.8.2-4.17.1 | SUSE-SU-2022:0211-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | strongswan | 5.9.5-1.1 | openSUSE-SU-2024:11808-1 |
| openSUSE Leap 15.3 | strongswan | 5.8.2-11.24.1 | openSUSE-SU-2022:0492-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | strongswan | 5.9.1-r4 | — |
| Alpine v3.23 | strongswan | 5.9.1-r4 | — |
| Alpine v3.22 | strongswan | 5.9.1-r4 | — |
| Alpine v3.21 | strongswan | 5.9.1-r4 | — |
| Alpine v3.20 | strongswan | 5.9.1-r4 | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | strongswan | 5.9.1-r4 | — |
| Alpine v3.18 | strongswan | 5.9.1-r4 | — |
| Alpine v3.17 | strongswan | 5.9.1-r4 | — |
| Alpine v3.16 | strongswan | 5.9.1-r4 | — |
| Alpine v3.15 | strongswan | 5.9.1-r4 | — |
| Alpine v3.14 | strongswan | 5.9.1-r3 | — |
| Alpine v3.13 | strongswan | 5.9.1-r2 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | strongswan | 5.9.5-1 | — |
Advisories 12
- USN-5250-2 strongswan vulnerability Ubuntu Security Notices (USN) · Jun 29, 2026
- USN-5250-1 strongswan vulnerability Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5056-1 strongswan - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2909-1 strongswan - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2022:14887-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:0202-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:0211-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:0492-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11808-1 strongswan-5.9.5-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- VDE-2022-010 PHOENIX CONTACT: Multiple Linux component vulnerabilities fixed in latest AXC F x152 LTS release CERT@VDE · May 22, 2025
- openSUSE-SU-2022:0492-1 Security update for strongswan SUSE / openSUSE Security Updates · May 7, 2025
- WID-SEC-2024-1023 strongSwan: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · May 5, 2024