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OpenAdvisories
Low · 2.1 CVE-2026-5772

MatchDomainName 1-Byte Stack Buffer Over-Read in Hostname Validation

Published Apr 9, 2026 · Updated Apr 10, 2026 · Assigned by wolfSSL

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

VendorProductAffectedFixed
wolfSSL wolfSSL ≤ 5.9.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 13 wolfssl No fix yet —
Debian 12 wolfssl No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 wolfssl No fix yet —
Ubuntu 26.04 LTS wolfssl No fix yet —
Ubuntu 25.10 wolfssl No fix yet —
Ubuntu 24.04 LTS wolfssl No fix yet —
Ubuntu 22.04 LTS wolfssl No fix yet —
Show 3 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS wolfssl No fix yet —
Ubuntu 18.04 LTS wolfssl No fix yet —
Ubuntu 16.04 LTS wolfssl No fix yet —
ReleasePackageFixed inAdvisory
Alpine v3.24 wolfssl 5.9.1-r0 —
Alpine v3.23 wolfssl 5.9.1-r0 —

References