Critical Integrity

CVE-2025-14265 — Improper server-side validation in ScreenConnect extension framework

In versions of ScreenConnect™ prior to 25.8, server-side validation and integrity checks within the extension subsystem could allow the installation and execution of untrusted or arbitrary extensions by authorized or administrative users. Abuse of this behavior could result in the execution of custom code on the server or unauthorized access to application configuration data. This issue affects only the ScreenConnect server component; host and guest clients are not impacted. ScreenConnect 25.8 introduces enhanced server-side configuration handling and integrity checks to ensure only trusted extensions can be installed.

Published Dec 11, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: ConnectWise

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.4% (30-day exploitation probability)+4
Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.37%

ahead of 29% of scored CVEs · Oct 14, 2026

Affects

Connectwise

Screenconnect

CVSS base

9.1

Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Connectwise Screenconnect).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (integrity), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Connectwise	Screenconnect	< 25.8.0.9438	Vulnerable	NIST National Vulnerability Database
Connectwise	Screenconnect	version All versions prior to 2025.8	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

High

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.1	CVSS 3.1	Critical	2.3	6.0	7d616e1a-3288-43b1-a0dd-0a65d3e70a49 via NIST National Vulnerability Database
9.1	CVSS 3.1	Critical	—	—	ConnectWise via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H (score shown at the top: 7d616e1a-3288-43b1-a0dd-0a65d3e70a49)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-494 · Download of Code Without Integrity Check

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.37%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · connectwise/screenconnect
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 9.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
2025
CVE published
Dec 11, 2025 · ConnectWise

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

www.connectwise.com/company/trust/security-bulletins/screenconnect-2025.8-security-patch
Vendor Advisory, NIST National Vulnerability Database

Elsewhere on this site

Connectwise
every CVE for this vendor

Integrity
same class

CWE-494
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-84869 ConnectWise ScreenConnect Improper Privilege Management and Missing Authorization Vulnerability KEV Sep 8, 2026
Medium CVE-2026-11596 In ScreenConnect™ versions prior to 26.2, input validation within the Host Pass creation… Jun 10, 2026
Critical CVE-2026-3564 ScreenConnect Instance Level Cryptographic Material Exposure Mar 17, 2026
Medium CVE-2025-14823 Certificate Signing Extension Returns Encrypted Values Dec 18, 2025
High CVE-2025-3935 ConnectWise ScreenConnect Improper Authentication Vulnerability KEV Apr 25, 2025
High CVE-2024-1708 ConnectWise ScreenConnect Path Traversal Vulnerability KEV Feb 21, 2024

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-14265 is "Improper server-side validation in ScreenConnect extension framework", rated Critical. It affects Screenconnect (Connectwise); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.1 describes technical severity. EPSS 0.37% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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