CVE-2026-4395
Wolfssl buffer overflow
- Published19 Mar 2026
Description
Heap-based buffer overflow in the KCAPI ECC code path of wc_ecc_import_x963_ex() in wolfSSL wolfcrypt allows a remote attacker to write attacker-controlled data past the bounds of the pubkey_raw buffer via a crafted oversized EC public key point. The WOLFSSL_KCAPI_ECC code path copies the input to key->pubkey_raw (132 bytes) using XMEMCPY without a bounds check, unlike the ATECC code path which includes a length validation. This can be triggered during TLS key exchange when a malicious peer sends a crafted ECPoint in ServerKeyExchange.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
Remediation
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-4395 being actively exploited?
CVE-2026-4395 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.59%.
How severe is CVE-2026-4395?
CVE-2026-4395 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.59% probability of exploitation.
Which products are affected by CVE-2026-4395?
Affected products include Wolfssl.
How do I fix CVE-2026-4395?
Upgrade affected software to a fixed version, for example Wolfssl 5.9.0 or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-4395 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.