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.
History

Fri, 10 Apr 2026 03:45:00 +0000

Type Values Removed Values Added
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.
Title Integer underflow in X.509 SAN parsing in wolfSSL
Weaknesses CWE-191
References
Metrics cvssV4_0

{'score': 2.3, 'vector': '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: wolfSSL

Published:

Updated: 2026-04-10T03:24:21.126Z

Reserved: 2026-03-30T19:57:35.065Z

Link: CVE-2026-5188

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-10T04:17:15.700

Modified: 2026-04-10T04:17:15.700

Link: CVE-2026-5188

cve-icon Redhat

No data.