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CVE-2026-5393

Wolfssl out-of-bounds read

9.1 CRITICALEPSS 0.31%
  1. Published9 Apr 2026

Description

Dual-Algorithm CertificateVerify out-of-bounds read. When processing a dual-algorithm CertificateVerify message, an out-of-bounds read can occur on crafted input. This can only occur when --enable-experimental and --enable-dual-alg-certs is used when building wolfSSL.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected products

Wolfssl< 5.9.1

Remediation

Fixed in
Wolfssl≥ 5.9.1

References

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Frequently asked

Is CVE-2026-5393 being actively exploited?

CVE-2026-5393 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.31%.

How severe is CVE-2026-5393?

CVE-2026-5393 has a CVSS 3.1 base score of 9.1, rated critical. EPSS estimates a 0.31% probability of exploitation.

Which products are affected by CVE-2026-5393?

Affected products include Wolfssl.

How do I fix CVE-2026-5393?

Upgrade affected software to a fixed version, for example Wolfssl 5.9.1 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.