CVE-2025-3935
HighExploitedPublic exploitScreenConnect versions 25.2.3 and earlier versions may be susceptible to a ViewState code injection attack.
Published Apr 25, 2025 · Updated Feb 26, 2026
Key Facts
Patch immediately- CVE-2025-3935 is a high-severity vulnerability (CVSS 7.2 v3.1) affecting ScreenConnect (Connectwise).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since May 30, 2025. Public exploit code is available.
- EPSS estimates a 3.5% probability of exploitation in the next 30 days.
- Fixed versions are available, including ScreenConnect 25.2.4.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.2
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
3.5%
Higher than 89.1% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2025-3935 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Jun 2, 2025 | Jun 23, 2025 | Not reported |
| Industry KEV feed | May 30, 2025 | Jun 23, 2025 | Not reported |
| CIRCL KEV | Jun 2, 2025 | Jun 23, 2025 | Not reported |
| ENISA EUVD | Jun 2, 2025 | n/a | Not reported |
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.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| ScreenConnectConnectwise | >= <25.2.3 | 25.2.4 |
Patched Releases
ScreenConnect
25.2.4
Timeline
Publicly disclosed
Apr 25, 2025
Added to Industry KEV feed
May 30, 2025
Added to CISA KEV
Jun 2, 2025
Added to CIRCL KEV
Jun 2, 2025
Added to ENISA EUVD
Jun 2, 2025
Last updated
Feb 26, 2026
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
- advisoryhttps://www.connectwise.com/company/trust/advisories
- advisoryhttps://www.connectwise.com/company/trust/security-bulletins/screenconnect-security-patch-2025.4
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
ScreenConnect versions 25.2.3 and earlier versions may be susceptible to a ViewState code injection attack.
Affected: ScreenConnect (Connectwise) versions >= <25.2.3. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since May 30, 2025.
Yes. It was added on Jun 2, 2025 with a federal remediation due date of Jun 23, 2025.
Public exploit code is available.
Fixed versions are available, including ScreenConnect 25.2.4.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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