wolfSSL up to 5.9.0 Hash/Digest certificate validation

CVSS Meta Temp Score
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CTI Interest Score
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6.9$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in wolfSSL up to 5.9.0. This affects an unknown function of the component Hash/Digest. The manipulation leads to certificate validation. This vulnerability is referenced as CVE-2026-5194. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in wolfSSL up to 5.9.0. It has been rated as critical. This issue affects some unknown processing of the component Hash/Digest. 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 confidentiality, integrity, and availability. The summary by CVE is:

Missing hash/digest size and OID checks allow digests smaller than allowed when verifying ECDSA certificates, or smaller than is appropriate for the relevant key type, to be accepted by signature verification functions. This could lead to reduced security of ECDSA certificate-based authentication if the public CA key used is also known. This affects ECDSA/ECC verification when EdDSA or ML-DSA is also enabled.

The weakness was published by Nicholas Carlini. The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-5194 since 03/31/2026. The exploitation is known to be difficult. The attack may be initiated remotely. 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 305902 (Linux Distros Unpatched Vulnerability : CVE-2026-5194), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.9.1 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (305902). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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Version

License

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: 7.0
VulDB Meta Temp Score: 6.9

VulDB Base Score: 5.0
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 9.1
NVD Vector: 🔒

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: 305902
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-5194

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: wolfSSL 5.9.1
Patch: github.com

Timelineinfo

03/31/2026 CVE reserved
04/10/2026 +10 days Advisory disclosed
04/10/2026 +0 days VulDB entry created
05/24/2026 +43 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Researcher: Nicholas Carlini
Status: Confirmed

CVE: CVE-2026-5194 (🔒)
GCVE (CVE): GCVE-0-2026-5194
GCVE (VulDB): GCVE-100-356705

Entryinfo

Created: 04/10/2026 06:19
Updated: 05/24/2026 01:45
Changes: 04/10/2026 06:19 (69), 04/11/2026 01:12 (2), 05/24/2026 01:45 (11)
Complete: 🔍
Cache ID: 216::103

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

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