CVE-2026-14957Network attack vectorHinoki check available

Unauthenticated daemon crash via malformed CERT payload

Published Sep 2, 2026 · Updated Sep 2, 2026

Reachable assertion in Libreswan 3.0 through 5.3.1 allows remote attackers to crash the pluto daemon via a malformed X.509 CERT payload. In add_decoded_cert(), CERT_ExtractPublicKey() can return NULL for an invalid public key, but FIPS-mode code asserts that the result is non-NULL. The pre-authentication path is reachable over IKEv1 or IKEv2 only when both the operating system and Libreswan use FIPS mode and at least one CA certificate is loaded; repeated payloads sustain the service interruption.

CVSS severity7.5
High
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Reachable assertion in Libreswan 3.0 through 5.3.1 allows remote attackers to crash the pluto daemon via a malformed X.509 CERT payload. In add_decoded_cert(), CERT_ExtractPublicKey() can return NULL for an invalid public key, but FIPS-mode code asserts that the result is non-NULL. The pre-authentication path is reachable over IKEv1 or IKEv2 only when both the operating system and Libreswan use FIPS mode and at least one CA certificate is loaded; repeated payloads sustain the service interruption.

The record

CVE
CVE-2026-14957
Published
Sep 2, 2026
Updated
Sep 2, 2026
Vendor
The Libreswan Project
Product
Libreswan
Classifications
CWE-617, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.0 <=5.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Libreswan Project · Libreswanversion=3.0 <=5.3.1

Published CVSS scores

5.9Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5Oracle LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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