wofSSL up to 5.8.x ECH Parser 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 was found in wofSSL up to 5.8.x. It has been declared as critical. This affects an unknown part of the component ECH Parser. Such manipulation leads to heap-based overflow. This vulnerability is referenced as CVE-2026-3549. It is possible to launch the attack remotely. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in wofSSL up to 5.8.x. It has been rated as critical. Affected by this issue is some unknown processing of the component ECH Parser. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to 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(). Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-3549 since 03/04/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 303180 (Linux Distros Unpatched Vulnerability : CVE-2026-3549), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.9.0 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (303180). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

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: 303180
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-3549

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: wofSSL 5.9.0
Patch: github.com

Timelineinfo

03/04/2026 CVE reserved
03/20/2026 +16 days Advisory disclosed
03/20/2026 +0 days VulDB entry created
03/26/2026 +6 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-3549 (🔒)
GCVE (CVE): GCVE-0-2026-3549
GCVE (VulDB): GCVE-100-351980

Entryinfo

Created: 03/20/2026 08:34
Updated: 03/26/2026 19:54
Changes: 03/20/2026 08:34 (67), 03/23/2026 16:50 (2), 03/24/2026 13:12 (1), 03/26/2026 19:54 (11)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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