CVE-2026-3549

Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/wolfSSL/wolfssl/pull/9817	Issue Tracking Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*

History

26 Mar 2026, 18:21

Type	Values Removed	Values Added
CPE		cpe:2.3:a:wolfssl:wolfssl::::::::
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.8
First Time		Wolfssl Wolfssl wolfssl
References	~~() https://github.com/wolfSSL/wolfssl/pull/9817 -~~	() https://github.com/wolfSSL/wolfssl/pull/9817 - Issue Tracking, Patch
Summary		(es) Desbordamiento de montículo en el análisis de ECH de TLS 1.3. Existía un desbordamiento negativo de enteros en la lógica de análisis de la extensión ECH al calcular la longitud de un búfer, lo que resultó en la escritura más allá de los límites de un búfer asignado. Tenga en cuenta que en wolfSSL, ECH está desactivado por defecto, y el estándar ECH aún está evolucionando.

19 Mar 2026, 21:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-03-19 21:17

Updated : 2026-03-26 18:21

NVD link : CVE-2026-3549

Mitre link : CVE-2026-3549

CVE.ORG link : CVE-2026-3549

JSON object : View

Products Affected

wolfssl

wolfssl

CWE

CWE-122

Heap-based Buffer Overflow

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