What’s Vulnerable › Vulnerabilities
CVE-2026-5772: MatchDomainName 1-Byte Stack Buffer Over-Read in Hostname Validation
- Severity: medium (CVSS 5.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-04-09 · updated 2026-06-17
- Weakness: CWE-126
Description
A 1-byte stack buffer over-read was identified in the MatchDomainName function (src/internal.c) during wildcard hostname validation when the LEFT_MOST_WILDCARD_ONLY flag is active. If a wildcard * exhausts the entire hostname string, the function reads one byte past the buffer without a bounds check, which could cause a crash.
Affected products
- wolfSSL: before 5.9.1 — fixed in 5.9.1
How to fix
Upgrade to a fixed version: wolfSSL 5.9.1. Check the vendor advisory for mitigations.
References
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