wolfssl up to 5.8.4 wc_ecc_import_x963_ex heap-based overflow

CVSS Meta Temp Score
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CTI Interest Score
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8.4$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in wolfssl up to 5.8.4. This issue affects the function wc_ecc_import_x963_ex. The manipulation results in heap-based overflow. This vulnerability is known as CVE-2026-4395. It is possible to launch the attack remotely. No exploit is available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in wolfssl up to 5.8.4. It has been classified as critical. Affected is the function wc_ecc_import_x963_ex. The manipulation with an unknown input leads to a heap-based overflow vulnerability. CWE is classifying the issue as CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was published by Haruto Kimura. The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-4395 since 03/18/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 303174 (Linux Distros Unpatched Vulnerability : CVE-2026-4395), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (303174). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 8.5
VulDB Meta Temp Score: 8.4

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 303174
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-4395

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: github.com

Timelineinfo

03/18/2026 CVE reserved
03/20/2026 +2 days Advisory disclosed
03/20/2026 +0 days VulDB entry created
03/26/2026 +6 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Researcher: Haruto Kimura
Status: Confirmed

CVE: CVE-2026-4395 (🔒)
GCVE (CVE): GCVE-0-2026-4395
GCVE (VulDB): GCVE-100-351960

Entryinfo

Created: 03/20/2026 08:25
Updated: 03/26/2026 19:54
Changes: 03/20/2026 08:25 (72), 03/22/2026 21:58 (1), 03/23/2026 18:35 (2), 03/24/2026 15:12 (1), 03/26/2026 19:54 (11)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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