VDB-374048 · CVE-2026-6450 · GCVE-0-2026-6450

wolfSSL up to 5.9.1 CRL certificate validation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
3.6	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as problematic has been found in wolfSSL up to 5.9.1. This issue affects some unknown processing of the component CRL Handler. Such manipulation leads to certificate validation. This vulnerability is listed as CVE-2026-6450. The attack may be performed from remote. There is no available exploit. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in wolfSSL up to 5.9.1. It has been rated as problematic. Affected by this issue is an unknown part of the component CRL Handler. The manipulation with an unknown input leads to a certificate validation vulnerability. Using CWE to declare the problem leads to CWE-295. The product does not validate, or incorrectly validates, a certificate. Impacted is integrity. CVE summarizes:

A CRL critical extension bypass exists in ParseCRL_Extensions where critical extensions are not properly enforced, allowing a crafted CRL with an unhandled critical extension to be accepted. This only affects builds with CRL support enabled and where a crafted CRL had a trusted signature when parsed.

The weakness was presented by Oleh Konko. The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-6450 since 04/16/2026. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1587.003.

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

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

wolfSSL

Version

License

open-source

Website

Product: https://github.com/wolfSSL/wolfssl/

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

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: github.com

Timelineinfo

04/16/2026 CVE reserved
06/25/2026 +70 days VulDB entry created
06/26/2026 +0 days Advisory disclosed
06/26/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Researcher: Oleh Konko
Status: Confirmed

CVE: CVE-2026-6450 (🔒)
GCVE (CVE): GCVE-0-2026-6450
GCVE (VulDB): GCVE-100-374048

Entryinfo

Created: 06/26/2026 01:20
Changes: 06/26/2026 01:20 (67)
Complete: 🔍
Cache ID: 216::103