Description
strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy. The earliest affected version is 5.3.0. An attack can occur via a crafted IKE_SA_INIT message.
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 | 5.9.12-1 | — |
| Debian 13 | strongswan | 5.9.12-1 | — |
| Debian 12 | strongswan | 5.9.8-5+deb12u1 | DSA-5560-1 |
| Debian 11 | strongswan | 5.9.1-1+deb11u4 | DSA-5560-1 |
| Debian 10 | strongswan | 5.7.2-1+deb10u4 | DLA-3663-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | strongswan | 5.9.5-2ubuntu2.2 | USN-6488-1 |
| Ubuntu 20.04 LTS | strongswan | 5.8.2-1ubuntu3.6 | USN-6488-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | strongswan | 5.6.2-1ubuntu2.9+esm1 | USN-6488-2 |
| Ubuntu Pro 16.04 LTS | strongswan | 5.3.5-1ubuntu3.8+esm4 | USN-6488-2 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | strongswan | 5.9.11-150500.5.6.1 | SUSE-SU-2023:4529-1 |
| SLES 15 SP4 | strongswan | 5.9.11-150400.19.17.2 | SUSE-SU-2023:4514-1 |
| SLES 15 SP3 | strongswan | 5.8.2-150200.11.42.2 | SUSE-SU-2023:4515-1 |
| SLES 15 SP2 | strongswan | 5.8.2-150200.11.42.2 | SUSE-SU-2023:4515-1 |
| SLES 15 SP1 | strongswan | 5.8.2-150000.4.23.2 | SUSE-SU-2023:4516-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP3 | strongswan | 5.8.2-150200.11.42.2 | SUSE-SU-2023:4515-1 |
| SLES for SAP 15 SP2 | strongswan | 5.8.2-150200.11.42.2 | SUSE-SU-2023:4515-1 |
| SLES for SAP 15 SP1 | strongswan | 5.8.2-150000.4.23.2 | SUSE-SU-2023:4516-1 |
| SLE HPC 15 SP3 | strongswan | 5.8.2-150200.11.42.2 | SUSE-SU-2023:4515-1 |
| SLE HPC 15 SP2 | strongswan | 5.8.2-150200.11.42.2 | SUSE-SU-2023:4515-1 |
| SLE HPC 15 SP1 | strongswan | 5.8.2-150000.4.23.2 | SUSE-SU-2023:4516-1 |
| SUSE Enterprise Storage 7.1 | strongswan | 5.8.2-150200.11.42.2 | SUSE-SU-2023:4515-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.5 | strongswan | 5.9.11-150500.5.6.1 | SUSE-SU-2023:4529-1 |
| openSUSE Leap 15.4 | strongswan | 5.9.11-150400.19.17.2 | SUSE-SU-2023:4514-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | strongswan | 5.9.12-r0 | — |
| Alpine v3.23 | strongswan | 5.9.12-r0 | — |
| Alpine v3.22 | strongswan | 5.9.12-r0 | — |
| Alpine v3.21 | strongswan | 5.9.12-r0 | — |
| Alpine v3.20 | strongswan | 5.9.12-r0 | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | strongswan | 5.9.12-r0 | — |
| Alpine v3.18 | strongswan | 5.9.12-r0 | — |
| Alpine v3.17 | strongswan | 5.9.12-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | strongswan | 5.9.12-1 | — |
| Azure Linux 2 (CBL-Mariner) | strongswan | 5.9.10-3 | — |
Advisories 9
- USN-6488-2 strongswan vulnerability Ubuntu Security Notices (USN) · Jun 25, 2026
- DSA-5560-1 strongswan - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3663-1 strongswan - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-6488-1 strongswan vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2023:4515-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:4516-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:4514-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-2972 strongSwan: Schwachstelle ermöglicht Codeausführung und DoS BSI CERT-Bund (WID) · Jul 8, 2025
- SUSE-SU-2023:4529-1 Security update for strongswan SUSE / openSUSE Security Updates · May 2, 2025