ConnectWise ScreenConnect signature verification

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.
8.5$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in ConnectWise ScreenConnect. Affected is an unknown function. The manipulation results in signature verification. This vulnerability is reported as CVE-2026-3564. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as critical, was found in ConnectWise ScreenConnect (version unknown). Affected is an unknown function. The manipulation with an unknown input leads to a signature verification vulnerability. CWE is classifying the issue as CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

A condition in the ScreenConnect server component may allow an actor with access to server-level cryptographic material used for authentication to obtain unauthorized access, including elevated privileges, in certain scenarios. ScreenConnect host and guest client agents are not independently affected by this CVE.

The advisory is shared for download at connectwise.com. This vulnerability is traded as CVE-2026-3564 since 03/04/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/11/2026).

The vulnerability scanner Nessus provides a plugin with the ID 303452 (ConnectWise ScreenConnect < 26.1 Authentication Bypass), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (303452) and EUVD (EUVD-2026-12574). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.5
VulDB Meta Temp Score: 8.5

VulDB Base Score: 8.1
VulDB Temp Score: 8.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.0
CNA Vector (ConnectWise): 🔒

CVSSv2info

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

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

Exploitinginfo

Class: Signature verification
CWE: CWE-347 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 303452
Nessus Name: ConnectWise ScreenConnect < 26.1 Authentication Bypass

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

03/04/2026 CVE reserved
03/17/2026 +13 days Advisory disclosed
03/17/2026 +0 days VulDB entry created
07/11/2026 +116 days VulDB entry last update

Sourcesinfo

Advisory: connectwise.com
Status: Confirmed

CVE: CVE-2026-3564 (🔒)
GCVE (CVE): GCVE-0-2026-3564
GCVE (VulDB): GCVE-100-351372
EUVD: 🔒

Entryinfo

Created: 03/17/2026 16:39
Updated: 07/11/2026 12:53
Changes: 03/17/2026 16:39 (60), 03/17/2026 17:33 (1), 03/21/2026 19:31 (1), 03/25/2026 04:10 (2), 07/11/2026 12:53 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Might our Artificial Intelligence support you?

Check our Alexa App!