Certificate trust bypass via wildcard SAN matching
Published Jun 25, 2026 · Updated Jun 25, 2026
Improper certificate validation in wolfSSL 3.9.10 through 5.9.1 allows remote attackers to bypass CA DNS name constraints with wildcard SANs. The DNS name-constraint matcher in wolfcrypt/src/asn.c compares SAN names without label-wise wildcard-aware subtree handling, so a prohibited *.example.com name can pass permitted or excluded constraints. Exploitation requires a certificate chain under a constrained issuing CA and changes only the verifier's trust decision for the prohibited name.
Summary
What happened
Improper certificate validation in wolfSSL 3.9.10 through 5.9.1 allows remote attackers to bypass CA DNS name constraints with wildcard SANs. The DNS name-constraint matcher in wolfcrypt/src/asn.c compares SAN names without label-wise wildcard-aware subtree handling, so a prohibited *.example.com name can pass permitted or excluded constraints. Exploitation requires a certificate chain under a constrained issuing CA and changes only the verifier's trust decision for the prohibited name.
The record
- CVE
- CVE-2026-10592
- Published
- Jun 25, 2026
- Updated
- Jun 25, 2026
- Vendor
- wolfSSL
- Product
- wolfSSL
- Classifications
- CWE-295
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 25, 2026CVE publishedPublication date reported by the CVE source.
- Jun 25, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.9.10 <=5.9.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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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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