High
libreswan — security advisory
Libreswan's pluto daemon has a use-after-free vulnerability when a client connecting using IKE over TCP closes the connection and another packet (retransmit or malicious) is received for the same tuple. IKE state is retained in memory after the client closes the connection, storing a pointer to iface_endpoint inside ike_sa.sa->st_iface_endpoint. Once this invalid pointer is used, the daemon crashes and restarts. This vulnerability can be triggered before the remote peer has authenticated itself. Continued exploitation can lead to a denial of service. Remote code execution could be possible. The IKE over TCP option is not enabled by default; only configurations that contain listen-tcp=yes are affected.
- Products
- libreswan
- Affected versions
- 3.20-7build1, 3.21-2, 3.22-1, 3.22-2, 3.22-3, 3.22-4, 3.23-1, 3.23-4, 3.29-2, 3.29-2build1, 3.32-3ubuntu3, 4.11-1ubuntu1, 4.12-1ubuntu1, 4.14-1ubuntu1, 4.14-1ubuntu2, 5.2-2.2ubuntu1, 5.2-2.2ubuntu2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-94453
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:33 UTC · Revision 1
Source evidence
Libreswan's pluto daemon has a use-after-free vulnerability when a client connecting using IKE over TCP closes the connection and another packet (retransmit or malicious) is received for the same tuple. IKE state is retained in memory after the client closes the connection, storing a pointer to iface_endpoint inside ike_sa.sa->st_iface_endpoint. Once this invalid pointer is used, the daemon crashes and restarts. This vulnerability can be triggered before the remote peer has authenticated itself. Continued exploitation can lead to a denial of service. Remote code execution could be possible. The IKE over TCP option is not enabled by default; only configurations that contain listen-tcp=yes are affected.
osv:UBUNTU-CVE-2026-94453
libreswan
Fixed versions: Not specified
libreswan
Fixed versions: Not specified
libreswan
Fixed versions: Not specified
libreswan
Fixed versions: Not specified
libreswan
Fixed versions: Not specified
libreswan
Fixed versions: Not specified
Complete source record
{
"id": "8d5626d7317141c137f54a3c865c5174f4eae0b502f1f7dbf3f69533a61e2f02",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-94453",
"method": "structured",
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"summary": "Libreswan's pluto daemon has a use-after-free vulnerability when a client connecting using IKE over TCP closes the connection and another packet (retransmit or malicious) is received for the same tuple. IKE state is retained in memory after the client closes the connection, storing a pointer to iface_endpoint inside ike_sa.sa->st_iface_endpoint. Once this invalid pointer is used, the daemon crashes and restarts. This vulnerability can be triggered before the remote peer has authenticated itself. Continued exploitation can lead to a denial of service. Remote code execution could be possible. The IKE over TCP option is not enabled by default; only configurations that contain listen-tcp=yes are affected.",
"evidence": "osv:UBUNTU-CVE-2026-94453",
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"modified": "2026-10-17T13:01:18.988773080Z",
"provider": "osv",
"upstream": [
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],
"references": [
"https://ubuntu.com/security/CVE-2026-94453",
"https://www.cve.org/CVERecord?id=CVE-2026-94453",
"https://libreswan.org/security/CVE-2026-94453/",
"https://libreswan.org/security/CVE-2026-94453/CVE-2026-94453.txt"
]
},
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"source_id": "core-osv",
"document_id": 361648,
"published_at": "2026-10-13T22:19:00+00:00"
}