CVE-2026-2646Heap-based Buffer Overflow in Wolfssl

Severity
5.0MEDIUMNVD
EPSS
0.0%
top 97.88%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedMar 19

Description

A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSL_d2i_SSL_SESSION() function. When deserializing session data with SESSION_CERTS enabled, certificate and session id lengths are read from an untrusted input without bounds validation, allowing an attacker to overflow fixed-size buffers and corrupt heap memory. A maliciously crafted session would need to be loaded from an external source to trigger this vulnerability. Internal sessions were not vulnerable.

CVSS vector

CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N

Affected Packages5 packages

🔴Vulnerability Details

2
OSV
CVE-2026-2646: A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSL_d2i_SSL_SESSION() function2026-03-19
GHSA
GHSA-24vq-qfc5-qrmj: A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSL_d2i_SSL_SESSION() function2026-03-19

📋Vendor Advisories

2
Microsoft
Heap buffer overflow in session parsing with wolfSSL_d2i_SSL_SESSION() function2026-03-10
Debian
CVE-2026-2646: wolfssl - A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSL_d2i_SSL_SESSION...2026

🕵️Threat Intelligence

1
Wiz
CVE-2026-2646 Impact, Exploitability, and Mitigation Steps | Wiz
CVE-2026-2646 — Heap-based Buffer Overflow in Wolfssl | cvebase