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.
Published: 2026-04-10
Score: 2.3 Low
EPSS: < 1% Very Low
KEV: No
Impact: Integer underflow during X.509 SAN parsing may lead to incorrect certificate handling.
Action: Assess Impact
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Wed, 29 Apr 2026 14:00:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H'}


Fri, 10 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 10 Apr 2026 09:00:00 +0000

Type Values Removed Values Added
First Time appeared Wolfssl
Wolfssl wolfssl
Vendors & Products Wolfssl
Wolfssl wolfssl

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: 2026-04-10T13:41:51.326Z

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

Link: CVE-2026-5188

cve-icon Vulnrichment

Updated: 2026-04-10T13:41:48.489Z

cve-icon NVD

Status : Analyzed

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

Modified: 2026-04-29T13:54:37.483

Link: CVE-2026-5188

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-10T09:26:53Z

Weaknesses