CVE-2026-3547
VU#948176: Multiple TLS Libraries can Bypass Delegation Enforcement
Published Mar 19, 2026 · corrected/updated Jun 17, 2026 · wolfssl wolfssl · evidence confidence high
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.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-3547 is a high public vulnerability record for wolfssl wolfssl. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether wolfssl wolfssl is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: wolfssl/wolfssl. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 7.5. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-125. Sources contributing to this record: certcc, cve_org, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Jun 17, 2026 · NIST NVD
Updated
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 comp
Oct 15, 2026 · CERT/CC Vulnerability Notes
Detected
Overview This note covers thirteen library-specific records (VU#948176.6, .8–.19) of how widely used TLS libraries apply X.509 Name Constraints. The records describe cases where a constrained name may be accepted by one library and rejected by another. Some are fixed, some remain under review, and some were not accepted as security issues. Description Name Constraints are meant to keep a subordina
Affected
- cpe wolfssl/wolfsslversion unspecified
Sources
- CERT/CC Vulnerability NotesGovernment advisoryCVE-2026-3547
Overview This note covers thirteen library-specific records (VU#948176.6, .8–.19) of how widely used TLS libraries apply X.509 Name Constraints. The records describe cases where a constrained name may be accepted by one library and rejected by another. Some are fixed, some remain
kb.cert.org - CVE.orgVulnerability recordCVE-2026-3547
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-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 pot
nvd.nist.gov