Parallels RAS Client RDP Backend Service Exposed Dangerous Function Local Privilege Escalation Vulnerability (CVE-2026-18263) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-18263

Parallels RAS Client RDP Backend Service Exposed Dangerous Function Local Privilege Escalation Vulnerability

Answer in brief

CVE-2026-18263 records a Unknown severity vulnerability in Parallels RAS Client RDP Backend Service Exposed Dangerous Function Local Privilege Escalation Vulnerability. The current sources do not mark it as known exploited. The current feed maps Parallels/RAS Client (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 20, 2026Updated Aug 20, 2026Source checked Aug 20, 2026First seen by HOL Aug 20, 2026Material review Aug 20, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Parallels/RAS Client (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Parallels/RAS Clientgeneric	21.0.26296	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Parallels/RAS Client.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 20, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 20, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 20, 2026

Sources and claim methodology

Source referencezerodayinitiative.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.