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Vulnerabilities

Vulnerability · CVE-2026-3547

VU#948176: Multiple TLS Libraries can Bypass Delegation Enforcement

Published Mar 19, 2026 · catalog updated Jun 17, 2026 · VU#948176: Multiple TLS Libraries

Check if you run it

No confirmed exploitation is on record for CVE-2026-3547. EPSS is 0.46%. Act only if a listed version of VU#948176: Multiple TLS Libraries is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (VU#948176: Multiple TLS Libraries).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.46%
Remediation
Version ranges on file
Affected products
cpe wolfssl/wolfssl · stated wolfssl

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe wolfssl/wolfsslversion unspecified
  • stated wolfssl<= 5.8.4

How to fix CVE-2026-3547

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-3547. EPSS is 0.46%. Act only if a listed version of VU#948176: Multiple TLS Libraries is installed.

Which versions are affected?

Compare what you have installed with <= 5.8.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-125: Out-of-bounds Read. EPSS 0.46%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Nginx security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. 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

  2. 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

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
  • FIRST EPSSExploitation probabilityCVE-2026-3547

    30-day exploitation probability 0.5%

    first.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

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.