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CVE-2025-3935

7.2, high Known exploited

ConnectWise ScreenConnect Improper Authentication Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab) CISA KEV catalogue (opens in a new tab)
CVSS
7.2, high high CVSS v3.1
EPSS, next 30 days
4% higher than 89.1% of scored CVEs
Exploitation
Confirmed in the wild
Published
25 Apr 2025a year ago

Known exploited

CISA added this to the Known Exploited Vulnerabilities Catalog on 2 Jun 2025. US federal agencies had to remediate by 23 Jun 2025, a deadline that has passed.

Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Description

ScreenConnect versions 25.2.3 and earlier versions may be susceptible to a ViewState code injection attack. ASP.NET Web Forms use ViewState to preserve page and control state, with data encoded using Base64 protected by machine keys. It is important to note that to obtain these machine keys, privileged system level access must be obtained. If these machine keys are compromised, attackers could create and send a malicious ViewState to the website, potentially leading to remote code execution on the server. The risk does not originate from a vulnerability introduced by ScreenConnect, but from platform level behavior. This had no direct impact to ScreenConnect Client. ScreenConnect 2025.4 patch disables ViewState and removes any dependency on it.

Details

Vendor
ConnectWise
Product
ScreenConnect
Weakness
CWE-502 (opens in a new tab)
Status
Analyzed
Updated
17 Jun 2026
Assigner
7d616e1a-3288-43b1-a0dd-0a65d3e70a49

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

References 3

Patches and fixes 1

Advisories 1

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other ConnectWise CVEs

Every ConnectWise CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-84869 ConnectWise ScreenConnect Improper Privilege Management and Missing Authorization Vulnerability KEV EPSS 0.9% 9.9, critical
  • CVE-2024-1708 ConnectWise ScreenConnect Path Traversal Vulnerability KEV EPSS 95% 8.4, high
  • CVE-2024-1709 ConnectWise ScreenConnect Authentication Bypass Vulnerability KEV EPSS 100% 10, critical

Beyond this page

Is CVE-2025-3935 in your network?

This page tells you how dangerous CVE-2025-3935 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

CVE-2025-3935 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.

  • EXYS7600 OCELOT

    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2025-3935 comes with the devices to patch.

    Learn more about EXYS7600 OCELOT

  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

    Learn more about EXYS7950 KONDRA
Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.