CVE-2026-4395: wolfSSL

Critical severity, CVSS 9.8. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• wolfSSL wolfSSL: before 5.9.0 (fixed in 5.9.0)

Published 2026-03-19. Last modified 2026-06-17.