CVE-2026-2646
Heap buffer overflow in session parsing with wolfSSL_d2i_SSL_SESSION() function
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.
INFO
Published Date :
March 19, 2026, 6:16 p.m.
Last Modified :
April 29, 2026, 6:42 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 50d2cd11-d01a-48ed-9441-5bfce9d63b27 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update wolfSSL to the latest version.
- Validate all session data lengths.
- Disable SESSION_CERTS if not needed.
Public PoC/Exploit Available at Github
CVE-2026-2646 has a 3 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-2646.
| URL | Resource |
|---|---|
| https://github.com/wolfSSL/wolfssl/pull/9748 | Issue Tracking Patch |
| https://github.com/wolfSSL/wolfssl/pull/9949 | Issue Tracking Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-2646 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-2646
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
CMake Dockerfile Shell C++ C Makefile Euphoria Batchfile Linker Script BitBake
test
CMake Dockerfile Shell C++ C Makefile Euphoria Batchfile Linker Script BitBake
None
CMake Dockerfile Shell C++ C Makefile Euphoria Batchfile Linker Script BitBake
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-2646 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-2646 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 29, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-787 Added CPE Configuration OR *cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:* versions up to (excluding) 5.9.0 Added Reference Type wolfSSL Inc.: https://github.com/wolfSSL/wolfssl/pull/9748 Types: Issue Tracking, Patch Added Reference Type wolfSSL Inc.: https://github.com/wolfSSL/wolfssl/pull/9949 Types: Issue Tracking, Patch -
New CVE Received by [email protected]
Mar. 19, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-122 Added Reference https://github.com/wolfSSL/wolfssl/pull/9748 Added Reference https://github.com/wolfSSL/wolfssl/pull/9949