Vulnerability · Published Mar 19, 2026 · Assigned by wolfSSL
CVE-2026-4395Heap-based buffer overflow in wc_ecc_import_x963_ex KCAPI path
Low 1.3
In plain English
A low-severity heap buffer overflow in wolfssl from wolfSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2026-4395 |
| Alpine:v3.24 | wolfssl | 5.9.0-r0 | ALPINE-CVE-2026-4395 |
| Debian:12 | wolfssl | no fix listed | DEBIAN-CVE-2026-4395 |
| Debian:13 | wolfssl | no fix listed | DEBIAN-CVE-2026-4395 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-4395 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-4395 |
| Ubuntu:25.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-4395 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-4395 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-4395 |
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/AU:Y/R:U/V:D/RE:L/U:Amber