What is CVE-2026-3547?

CVE-2026-3547 is a high-severity vulnerability in Wolfssl, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-03-19.

How severe is CVE-2026-3547?

High severity. CVSS v3 base score is 7.5 out of 10.

Out-of-bounds Read in Wolfssl

CVE-2026-3547

Out-of-bounds read in ALPN parsing due to incomplete validation. wolfSSL 5.8.4 and earlier contained an out-of-bounds read in ALPN handling when built with ALPN enabled (HAVE_ALPN / --enable-alpn). A crafted ALPN protocol list could trigger an out-of-bounds read, leading to a potential process crash (denial of service). Note that ALPN is disabled by default, but is enabled for these 3rd party compatibility features: enable-apachehttpd, enable-bind, enable-curl, enable-haproxy, enable-hitch, enable-lighty, enable-jni, enable-nginx, enable-quic.

Vulnerability class: Buffer Overflow

EPSS: 0.003 (17.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Wolfssl — versions 0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

facts@wolfssl.com (Patch, patch, Issue Tracking)

Frequently asked questions

What is CVE-2026-3547?: CVE-2026-3547 is a high-severity vulnerability in Wolfssl, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-03-19.
How severe is CVE-2026-3547?: High severity. CVSS v3 base score is 7.5 out of 10.