HOMEVULNERABILITIESCVE-2026-3547
HIGH

CVE-2026-3547

CWE-125Published: March 19, 2026· Updated: Mar 26, 2026

7.5
CVSS v3.1
EPSS:0.04%probability of exploitation in 30 daysPercentile:11.1th

Official Description

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.

NVD Source

Technical Analysis

CVE-2026-3547 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

wolfssl1 product
wolfssl
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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Official Patches & Advisories

PATCHhttps://github.com/wolfSSL/wolfssl/pull/9859

All References (1)

→
https://github.com/wolfSSL/wolfssl/pull/9859Issue Tracking · Patch

Quick Facts

CVE IDCVE-2026-3547
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-125
CISA KEVNo
EPSS (30d)0.04%
Affected1 vendor
PublishedMar 19, 2026

Related CVEs (CWE-125)

CVE-2026-34987
9.9
CVE-2026-24213
9.8
CVE-2026-33642
9.8
CVE-2025-15646
9.8
CVE-2026-42799
9.8
CVE-2026-14420
9.6

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-3547 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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