Cerberus FTP Server: Path Traversal: 'UNCsharename' (Windows UNC Share)
CVE-2026-82819 is a high-severity path traversal: 'uncsharename' (windows UNC share) vulnerability in Cerberus FTP Server from Cerberus, with a CVSS 4.0 base score of 7.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2026.3.0 as the first without the flaw, so updating Cerberus FTP Server to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.46% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Cerberus FTP Server to 2026.3.0 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cerberus | Cerberus FTP Server | before 2026.3.0 | 2026.3.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- NoneNo loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- NoneNo loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA.
Official description
A vulnerability in Cerberus FTP Server allows an authenticated remote attacker to perform UNC path injection via a manipulated parameter. By supplying a malicious SMB share path, an attacker can execute authentication coercion against the underlying server, resulting in the leakage of the Cerberus service account's Net-NTLMv2 hash. This issue has been resolved in Cerberus FTP Server: 2026.3.0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Path Traversal: 'UNCsharename' (Windows UNC Share)
The product accepts input that identifies a Windows UNC share ('UNCsharename') that potentially redirects access to an unintended location or arbitrary file.
How developers prevent this class of flaw
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
More Path Traversal: 'UNCsharename' (Windows UNC Share) vulnerabilities (CWE-40)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Cerberus FTP Server
- 8.8 High severity
- 7.5 High severity
Recent Path Traversal: 'UNCsharename' (Windows UNC Share) vulnerabilities
- 8.8 High severity
Spotted an error? Tell us.