CVE-2026-3547

highpriority · track · 0EPSS 0.003 · 21 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.29% (21st) EPSS

CVSS 7.5 · high

Is it mine?

2 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · cert_cc_vince

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · facts@wolfssl.comexploitability 3.9 · impact 3.6

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-125US

affected products (2)

Products and version ranges known to be affected.

wolfSSL wolfSSL0 → 5.9.0enisa_euvdEU
wolfssl wolfssl< 5.9.0nvdUScpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

VU#948176CERT/CC Vulnerability Note VU#9481762026-10-14vendor · cert_cc_vinceUS

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd cert_cc_vince NVD CVE.org MITRE

published 2026-03-19modified 2026-06-17

references (4)

External citations — patches, advisories, analysis.

scry

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