wolfSSL up to 5.8.4 Session wolfSSL_d2i_SSL_SESSION heap-based overflow

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.4$0-$5k0.00

Summaryinfo

A vulnerability has been found in wolfSSL up to 5.8.4 and classified as critical. This vulnerability affects the function wolfSSL_d2i_SSL_SESSION of the component Session Handler. This manipulation causes heap-based overflow. The identification of this vulnerability is CVE-2026-2646. It is possible to initiate the attack remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in wolfSSL up to 5.8.4. Affected by this vulnerability is the function wolfSSL_d2i_SSL_SESSION of the component Session Handler. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is 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(). As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was shared by Jonathan Bar Or. It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-2646 since 02/17/2026. The exploitation appears to be difficult. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 303235 (Linux Distros Unpatched Vulnerability : CVE-2026-2646), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (303235) and EUVD (EUVD-2026-13137). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

Version

License

Website

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: 6.5
VulDB Meta Temp Score: 6.4

VulDB Base Score: 5.0
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 8.1
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

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

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Proof-of-Concept

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 303235
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-2646

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

02/17/2026 CVE reserved
03/19/2026 +30 days Advisory disclosed
03/19/2026 +0 days VulDB entry created
05/05/2026 +47 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Researcher: Jonathan Bar Or
Status: Confirmed

CVE: CVE-2026-2646 (🔒)
GCVE (CVE): GCVE-0-2026-2646
GCVE (VulDB): GCVE-100-351739
EUVD: 🔒

Entryinfo

Created: 03/19/2026 18:56
Updated: 05/05/2026 17:46
Changes: 03/19/2026 18:56 (68), 03/19/2026 19:35 (1), 03/22/2026 19:37 (2), 03/22/2026 20:43 (2), 03/24/2026 06:34 (1), 05/05/2026 17:46 (11)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!