ScreenConnect Client: Guest-to-Host File Execution via File-Transfer Actions
A condition in the ScreenConnect client may allow files to be transferred and executed through an active remote session without authorization or Host confirmation in certain circumstances. ScreenConnect servers are not impacted.
- Published
- Sep 8, 2026
- Updated
- Sep 12, 2026
- EPSS
- 0.9% · 59th percentile
- CWE
- CWE-269
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Report tools
Action score
69
This week
Don’t wait for the next maintenance window.
- CVSS
- 39 / 40 · 9.9 / 10
- CISA KEV
- 30 / 30 · Listed
- EPSS
- 0 / 30 · 0.9%
CISA SSVC decision
- Exploitation
- active
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · ConnectWise
- 9.9
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Actively exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on Sep 11, 2026. That signals real attacks, not theory.
Remediation deadline for government agencies: Sep 14, 2026.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| connectwise | screenconnect | cpe:2.3:a:connectwise:screenconnect |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- connectwise screenconnectbefore 26.6.5.9742
Versions reported by the vendor
Affected version ranges reported by the assigning authority (ConnectWise). Independent of NVD's CPE analysis and usually ahead of it.
ConnectWise ScreenConnect
- All versions prior to 26.6.5affected
Same product
connectwise: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-1709Authentication bypass using an alternate path or channelKEV100Now
- CVE-2024-1708Improper limitation of a pathname to a restricted directory (“path traversal”)KEV92Now
- CVE-2025-3935ScreenConnect Exposure to ASP.NET ViewState Code InjectionKEV59Plan
- CVE-2026-3564ScreenConnect Instance Level Cryptographic Material Exposure36Monitor
- CVE-2025-14265Improper server-side validation in ScreenConnect extension framework36Monitor
- CVE-2025-14823Certificate Signing Extension Returns Encrypted Values21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- CISA KEV+2 d
- TodaySep 29, 2026+21 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-269 · Improper Privilege ManagementCVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
nvd-secondary
Root cause
To simplify setup, a service account is granted broad, cluster-wide permissions. The principle of least privilege is skipped during installation.
The bug in code
The whole CWE-269 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
kind: ClusterRolerules: - apiGroups: ["*"] resources: ["*"] verbs: ["*"]Fixed
kind: Rolemetadata: namespace: lodos-systemrules: - apiGroups: ["apps"] resources: ["deployments"] verbs: ["get", "list", "update"]Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- github.com/ConnectWise-Advisories/Disclosures/tree/main/CVE-2026-84869
- www.connectwise.com/company/trust/advisories
- www.connectwise.com/company/trust/security-bulletins/2026-09-08-screenconnect-bulletin
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-84869
- www.huntress.com/blog/rogue-screenconnect-installations
Vendor advisories and official records. Exploit/PoC links are deliberately left out.