CVE-2026-12413: Off-by-one Error in The Libreswan Project libreswan
An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemble_v2_incoming_fragments() would ignore unknown outer payloads but still store these in a fixed size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md->digest_roof < elemsof(md->digest)) causes the daemon to abort. No remote code execution is possible. Any configuration that allows IKEv2 connections that do not set fragmentation=no are vulnerable. IKEv1 is not affected.
AI Analysis
Technical Summary
The vulnerability in Libreswan 4.6 involves the function reassemble_v2_incoming_fragments() which processes IKEv2 fragments. Unknown outer payloads are ignored but still stored in a fixed-size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md->digest_roof < elemsof(md->digest)) causes the pluto daemon to abort when the array boundary is exceeded. This leads to a denial of service by crashing and restarting the daemon. Only configurations allowing IKEv2 connections without fragmentation disabled (fragmentation != no) are vulnerable. IKEv1 is unaffected and no remote code execution is possible.
Potential Impact
Successful exploitation causes the Libreswan pluto daemon to crash and restart repeatedly, resulting in a denial of service. There is no impact on confidentiality or integrity, and no remote code execution is possible. The service disruption affects VPN availability for affected configurations.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, it is recommended to disable IKEv2 fragmentation by setting fragmentation=no in the configuration to prevent exploitation. Monitoring for malformed IKEv2 fragments and restricting access to IKEv2 services may reduce exposure.
CVE-2026-12413: Off-by-one Error in The Libreswan Project libreswan
Description
An invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service. The function reassemble_v2_incoming_fragments() would ignore unknown outer payloads but still store these in a fixed size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md->digest_roof < elemsof(md->digest)) causes the daemon to abort. No remote code execution is possible. Any configuration that allows IKEv2 connections that do not set fragmentation=no are vulnerable. IKEv1 is not affected.
CVSS v3.1
Score 7.5high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Libreswan 4.6 involves the function reassemble_v2_incoming_fragments() which processes IKEv2 fragments. Unknown outer payloads are ignored but still stored in a fixed-size array msg_digest.digest[PAYLIMIT]. An off-by-one error in the assertion PASSERT(logger, md->digest_roof < elemsof(md->digest)) causes the pluto daemon to abort when the array boundary is exceeded. This leads to a denial of service by crashing and restarting the daemon. Only configurations allowing IKEv2 connections without fragmentation disabled (fragmentation != no) are vulnerable. IKEv1 is unaffected and no remote code execution is possible.
Potential Impact
Successful exploitation causes the Libreswan pluto daemon to crash and restart repeatedly, resulting in a denial of service. There is no impact on confidentiality or integrity, and no remote code execution is possible. The service disruption affects VPN availability for affected configurations.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, it is recommended to disable IKEv2 fragmentation by setting fragmentation=no in the configuration to prevent exploitation. Monitoring for malformed IKEv2 fragments and restricting access to IKEv2 services may reduce exposure.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- libreswan
- Date Reserved
- 2026-06-16T15:52:12.674Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a46d9e827e9c79719236155
Added to database: 07/02/2026, 21:36:40 UTC
Last enriched: 07/02/2026, 21:51:16 UTC
Last updated: 07/02/2026, 22:51:39 UTC
Views: 3
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