CVE-2026-14957
FIPS mode assertion failure via malicious CERT payload
Description
In FIPS mode, Libreswan's add_decoded_cert() function calls CERT_ExtractPublicKey() and asserts that the result is not NULL. However, CERT_ExtractPublicKey() returns NULL when public key extraction fails, for example if the RSA exponent is set to 0. A remote attacker can send a malformed X.509 certificate in a CERT payload to trigger the assertion, causing the pluto daemon to abort and restart. Continued exploitation causes a denial of service. No remote code execution is possible. Both IKEv1 and IKEv2 are affected. The vulnerability is only exploitable when both the OS and libreswan are running in FIPS mode and at least one CA certificate is loaded. The CERT payload is processed before peer authentication, so no credentials are needed to exploit this. Configurations using only PreSharedKey (PSK) authentication with no CA certificates loaded in the NSS database are not vulnerable.
INFO
Published Date :
Sept. 2, 2026, 3:16 a.m.
Last Modified :
Sept. 2, 2026, 3:16 a.m.
Remotely Exploit :
Yes !
Source :
d42dc95b-23f1-4e06-9076-20753a0fb0df
Affected Products
The following products are affected by CVE-2026-14957
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | d42dc95b-23f1-4e06-9076-20753a0fb0df |
Solution
- Disable FIPS mode if possible.
- Update Libreswan to the latest version.
- Avoid loading CA certificates in FIPS mode.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-14957.
| URL | Resource |
|---|---|
| https://libreswan.org/security/CVE-2026-14957/ | |
| https://libreswan.org/security/CVE-2026-14957/CVE-2026-14957.txt |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-14957 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-14957
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-14957 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-14957 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by d42dc95b-23f1-4e06-9076-20753a0fb0df
Sep. 02, 2026
Action Type Old Value New Value Added Description In FIPS mode, Libreswan's add_decoded_cert() function calls CERT_ExtractPublicKey() and asserts that the result is not NULL. However, CERT_ExtractPublicKey() returns NULL when public key extraction fails, for example if the RSA exponent is set to 0. A remote attacker can send a malformed X.509 certificate in a CERT payload to trigger the assertion, causing the pluto daemon to abort and restart. Continued exploitation causes a denial of service. No remote code execution is possible. Both IKEv1 and IKEv2 are affected. The vulnerability is only exploitable when both the OS and libreswan are running in FIPS mode and at least one CA certificate is loaded. The CERT payload is processed before peer authentication, so no credentials are needed to exploit this. Configurations using only PreSharedKey (PSK) authentication with no CA certificates loaded in the NSS database are not vulnerable. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-252 Added CWE CWE-617 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/14xxx/CVE-2026-14957.json">CVE-2026-14957</a> Added Reference https://libreswan.org/security/CVE-2026-14957/ Added Reference https://libreswan.org/security/CVE-2026-14957/CVE-2026-14957.txt