libreswan up to 5.3/5.3.0 reassemble_v2_incoming_fragments digest_roof off-by-one

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k1.43+

Summaryinfo

A vulnerability, which was classified as problematic, has been found in libreswan up to 5.3/5.3.0. Affected by this vulnerability is the function reassemble_v2_incoming_fragments. The manipulation of the argument digest_roof leads to off-by-one. This vulnerability is listed as CVE-2026-12413. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in libreswan up to 5.3/5.3.0. This issue affects the function reassemble_v2_incoming_fragments. The manipulation of the argument digest_roof with an unknown input leads to a off-by-one vulnerability. Using CWE to declare the problem leads to CWE-193. A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. Impacted is availability. The summary by CVE is:

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 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.

The weakness was presented by Hu Xinyao. The advisory is shared at libreswan.org. The identification of this vulnerability is CVE-2026-12413 since 06/16/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available.

Upgrading to version 5.3.1 eliminates this vulnerability.

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Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (libreswan): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Off-by-one
CWE: CWE-193 / CWE-189
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: libreswan 5.3.1

Timelineinfo

06/16/2026 CVE reserved
07/03/2026 +17 days Advisory disclosed
07/03/2026 +0 days VulDB entry created
07/03/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: libreswan.org
Researcher: Hu Xinyao
Status: Confirmed

CVE: CVE-2026-12413 (🔒)
GCVE (CVE): GCVE-0-2026-12413
GCVE (VulDB): GCVE-100-376013

Entryinfo

Created: 07/03/2026 06:19
Changes: 07/03/2026 06:19 (64)
Complete: 🔍
Cache ID: 216::103

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