CVE-2026-5188

Published Apr 10, 2026

Last updated 2 days ago

Overview

Description
An integer underflow issue exists in wolfSSL when parsing the Subject Alternative Name (SAN) extension of X.509 certificates. A malformed certificate can specify an entry length larger than the enclosing sequence, causing the internal length counter to wrap during parsing. This results in incorrect handling of certificate data. The issue is limited to configurations using the original ASN.1 parsing implementation which is off by default.
Source
facts@wolfssl.com
NVD status
Analyzed
Products
wolfssl

Risk scores

CVSS 4.0

Type
Secondary
Base score
2.3
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/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:X
Severity
LOW

CVSS 3.1

Type
Primary
Base score
8.1
Impact score
5.2
Exploitability score
2.8
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Severity
HIGH

Weaknesses

facts@wolfssl.com
CWE-191

Social media

Hype score
Not currently trending

Configurations

References

Sources include official advisories and independent security research.