PT-2026-31721 · Wolfssl · Wolfssl

Nicholas Carlini

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Published

2026-04-09

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Updated

2026-04-13

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CVE-2026-5194

CVSS v4.0

9.3

Critical

AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:H/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Red
Name of the Vulnerable Software and Affected Versions wolfSSL versions prior to 5.9.1
Description A security flaw exists in wolfSSL where missing hash/digest size and OID checks allow digests smaller than expected when verifying ECDSA certificates. This can lead to the acceptance of undersized digests during ECDSA signature verification, potentially reducing the security of certificate-based authentication. This issue affects ECDSA/ECC verification when EdDSA or ML-DSA is also enabled. The library is used in a wide range of products, including VPN applications, home routers, automotive systems, power grid infrastructure, and military systems, and is estimated to be present on billions of devices worldwide. The flaw allows forged digital identities to be accepted as genuine, potentially leading to the trust of malicious servers, files, or connections. The vulnerability impacts all signature verification algorithms in the library, including PQC ML-DSA.
Recommendations Update to wolfSSL version 5.9.1 or later.

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

CVE-2026-5194

Affected Products

Wolfssl