Certificate trust bypass via omitted URI constraint checks
Published Apr 9, 2026 · Updated Apr 9, 2026
Improper certificate validation in wolfSSL before 5.9.1 allows remote attackers controlling a sub-CA to bypass URI name constraints. ConfirmNameConstraints() omits ASN_URI_TYPE from its nameTypes loop, so URI SAN values are never compared against permitted or excluded URI constraints. Control of a constrained intermediate CA is required; accepted out-of-scope leaf certificates can impersonate unauthorized URI identities.
Summary
What happened
Improper certificate validation in wolfSSL before 5.9.1 allows remote attackers controlling a sub-CA to bypass URI name constraints. ConfirmNameConstraints() omits ASN_URI_TYPE from its nameTypes loop, so URI SAN values are never compared against permitted or excluded URI constraints. Control of a constrained intermediate CA is required; accepted out-of-scope leaf certificates can impersonate unauthorized URI identities.
The record
- CVE
- CVE-2026-5263
- Published
- Apr 9, 2026
- Updated
- Apr 9, 2026
- Vendor
- wolfSSL
- Product
- wolfSSL
- Classifications
- CWE-295
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Apr 9, 2026CVE publishedPublication date reported by the CVE source.
- Apr 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <5.9.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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