CVE-2026-4395 Heap-based buffer overflow in wc_ecc_import_x963_ex KCAPI path
A remote attacker can trigger a heap-based buffer overflow in wolfSSL's KCAPI ECC path via a crafted EC public key, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-4395?
CVE-2026-4395 is a low-severity memory corruption vulnerability in Wolfssl Wolfssl, published on 19 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-122
Which versions are affected by CVE-2026-4395?
It affects 1 product.
Products include Wolfssl Wolfssl.
How do I fix CVE-2026-4395?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-4395 being exploited?
There is no known exploitation of CVE-2026-4395 in the wild and no public exploit code.
Other vulnerabilities in Wolfssl Wolfssl
Sources
Also known as DEBIAN-CVE-2026-4395, GHSA-cqx9-3cpj-rrqp, JLSEC-2026-713, UBUNTU-CVE-2026-4395.