Reachable assertion in libreswan - CVE-2026-12413
Published: June 25, 2026
Vulnerability identifier: #VU135208
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: CVE-2026-12413
CWE-ID: CWE-617
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: libreswan.org
Affected software:
libreswan
libreswan
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an assertion failure caused by improper bounds checking in reassemble_v2_incoming_fragments() when processing invalidly formatted IKEv2 fragments. A remote attacker can send specially crafted fragmented IKEv2 packets to cause a denial of service.
Only IKEv2 configurations with fragmentation enabled are vulnerable. IKEv1 is not affected.
How to mitigate CVE-2026-12413
Install security update from vendor's website.