Medium severity · published Apr 9, 2026
CVE-2026-5263
URI nameConstraints not enforced in ConfirmNameConstraints()
6.5
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WO
wolfSSL · wolfSSL
before 5.9.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5263
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-5263
Issue Tracking
https://github.com/wolfSSL/wolfssl/pull/10048
www.talosintelligence.com
https://www.talosintelligence.com/vulnerability_reports/TALOS-2026-2410
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