wolfSSL up to 5.9.1 certificate validation

CVSS Meta Temp Score
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CTI Interest Score
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3.6$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in wolfSSL up to 5.9.1. Affected by this vulnerability is an unknown functionality. Performing a manipulation results in certificate validation. This vulnerability is identified as CVE-2026-6731. The attack can be initiated remotely. There is not any exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability classified as problematic has been found in wolfSSL up to 5.9.1. This affects some unknown processing. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on integrity. The summary by CVE is:

X.509 name constraint bypass via the Subject Common Name when treated as a DNS-type name. A certificate whose Subject CN violates an issuing CA's DNS name constraints could be accepted.

The weakness was released by D0Sf3T. The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-6731 since 04/20/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1587.003 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 323827 (Linux Distros Unpatched Vulnerability : CVE-2026-6731), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (323827). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.6

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Certificate validation
CWE: CWE-295 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 323827
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-6731

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: github.com

Timelineinfo

04/20/2026 CVE reserved
06/26/2026 +67 days Advisory disclosed
06/26/2026 +0 days VulDB entry created
07/01/2026 +5 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Researcher: D0Sf3T
Status: Confirmed

CVE: CVE-2026-6731 (🔒)
GCVE (CVE): GCVE-0-2026-6731
GCVE (VulDB): GCVE-100-374121

Entryinfo

Created: 06/26/2026 08:03
Updated: 07/01/2026 13:15
Changes: 06/26/2026 08:03 (66), 07/01/2026 13:15 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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