Description
URI nameConstraints from constrained intermediate CAs are parsed but not enforced during certificate chain verification in wolfcrypt/src/asn.c. A compromised or malicious sub-CA could issue leaf certificates with URI SAN entries that violate the nameConstraints of the issuing CA, and wolfSSL would accept them as valid.
Published: 2026-04-09
Score: 7 High
EPSS: < 1% Very Low
KEV: No
Impact: Certificate Trust Bypass
Action: Immediate Patch
AI Analysis

Impact

The vulnerability originates in the ConfirmNameConstraints() routine in wolfSSL's certificate verification component, where URI name constraints imported from constrained intermediate CAs are parsed but not enforced. This allows a malicious or compromised sub‑CA to issue a leaf certificate containing a URI Subject Alternative Name that violates the parent CA's constraints. Consequently, wolfSSL would accept the certificate as valid, effectively bypassing the intended naming policy and allowing the use of unauthorized URIs within the TLS connection.

Affected Systems

All deployments that use wolfSSL for TLS are potentially affected, as the flaw exists in the open‑source wolfcrypt library and is present in all builds until patched. Any application or device that does not enforce its own URI SAN validation and relies on wolfSSL for certificate chain verification is susceptible.

Risk and Exploitability

The CVSS base score of 7 indicates high risk. EPSS data is not provided, but the vulnerability is not listed in the CISA KEV catalog, suggesting no known public exploitation yet. Attackers would need a sub‑CA capable of creating certificates and could use a compromised internal CA or an attacker‑controlled CA. Because the attack only requires certificate issuance, the threat is realistic, especially in environments where cross‑CA trust is present. Operators should treat this as a high‑risk flaw and apply the vendor‑supplied patch promptly.

Generated by OpenCVE AI on April 9, 2026 at 23:06 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the latest wolfSSL patch that enforces URI nameConstraints during certificate verification.
  • If a patch is not yet available, restrict the use of wolfSSL to certificates issued by fully trusted CAs that do not rely on URI SANs.
  • Verify that your application performs additional validation of URI SAN entries if possible.
  • Keep the library updated and monitor the vendor’s advisory for future releases.

Generated by OpenCVE AI on April 9, 2026 at 23:06 UTC.

Tracking

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Advisories

No advisories yet.

History

Wed, 29 Apr 2026 17:30:00 +0000

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

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N'}


Fri, 10 Apr 2026 18:15:00 +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

Thu, 09 Apr 2026 21:45:00 +0000

Type Values Removed Values Added
Description URI nameConstraints from constrained intermediate CAs are parsed but not enforced during certificate chain verification in wolfcrypt/src/asn.c. A compromised or malicious sub-CA could issue leaf certificates with URI SAN entries that violate the nameConstraints of the issuing CA, and wolfSSL would accept them as valid.
Title URI nameConstraints not enforced in ConfirmNameConstraints()
Weaknesses CWE-295
References
Metrics cvssV4_0

{'score': 7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:L/VA:N/SC:H/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: wolfSSL

Published:

Updated: 2026-04-10T18:09:12.862Z

Reserved: 2026-03-31T16:56:07.521Z

Link: CVE-2026-5263

cve-icon Vulnrichment

Updated: 2026-04-10T18:09:08.258Z

cve-icon NVD

Status : Analyzed

Published: 2026-04-09T22:16:36.647

Modified: 2026-04-29T17:19:55.047

Link: CVE-2026-5263

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-10T09:29:00Z

Weaknesses