RAS Client: Exposed Dangerous Method or Function
CVE-2026-18263 is a high-severity exposed dangerous method or function vulnerability in RAS Client from Parallels, with a CVSS 3.0 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected RAS Client versions: 21.0.26296. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.17% 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
- Check which version of RAS Client you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Parallels | RAS Client | 21.0.26296 | Not stated |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (trendmicro.com).
Official description
Parallels RAS Client RDP Backend Service Exposed Dangerous Function Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Parallels RAS Client. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the RAS RDP Backend Service. The issue results from an exposed dangerous function. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-28886.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Exposed Dangerous Method or Function
The product provides an Applications Programming Interface (API) or similar interface for interaction with external actors, but the interface includes a dangerous method or function that is not properly restricted.
How developers prevent this class of flaw
- If you must expose a method, make sure to perform input validation on all arguments, limit access to authorized parties, and protect against all possible vulnerabilities.
- Identify all exposed functionality. Explicitly list all functionality that must be exposed to some user or set of users. Identify which functionality may be: accessible to all users restricted to a small set of privileged users prevented from being directly accessible at all Ensure that the implemented code follows these expectations. This includes setting the appropriate access modifiers where applicable (public, private, protected, etc.) or not marking ActiveX controls safe-for-scripting.
More Exposed Dangerous Method or Function vulnerabilities (CWE-749)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in RAS Client
- 7.8 High severity
- 7.8 High severity
Recent Exposed Dangerous Method or Function vulnerabilities
- 7.2 High severity
- 7.5 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.1 Critical severity
- 9.9 Critical severity
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