ZDI-26-556: 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 ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-18263.
AI Analysis
Technical Summary
CVE-2026-18263 is a local privilege escalation vulnerability in the Parallels RAS Client RDP Backend Service caused by an exposed dangerous function. An attacker with low-privileged code execution on the affected system can leverage this flaw to escalate privileges to SYSTEM level and execute arbitrary code. The vulnerability was reported to Parallels on 2026-02-25 and publicly disclosed on 2026-08-11. Parallels addressed the issue in version 21.2 of the RAS Client.
Potential Impact
If exploited, an attacker who already has the ability to run low-privileged code on the system can escalate their privileges to SYSTEM, gaining full control over the affected machine. This can lead to complete compromise of the system, including confidentiality, integrity, and availability impacts.
Mitigation Recommendations
Parallels has released an official fix for this vulnerability in version 21.2 of the RAS Client. Users should upgrade to version 21.2 or later to remediate this issue. No additional mitigation steps are indicated by the vendor advisory.
ZDI-26-556: Parallels RAS Client RDP Backend Service Exposed Dangerous Function Local Privilege Escalation Vulnerability
Description
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 ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-18263.
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-18263 is a local privilege escalation vulnerability in the Parallels RAS Client RDP Backend Service caused by an exposed dangerous function. An attacker with low-privileged code execution on the affected system can leverage this flaw to escalate privileges to SYSTEM level and execute arbitrary code. The vulnerability was reported to Parallels on 2026-02-25 and publicly disclosed on 2026-08-11. Parallels addressed the issue in version 21.2 of the RAS Client.
Potential Impact
If exploited, an attacker who already has the ability to run low-privileged code on the system can escalate their privileges to SYSTEM, gaining full control over the affected machine. This can lead to complete compromise of the system, including confidentiality, integrity, and availability impacts.
Mitigation Recommendations
Parallels has released an official fix for this vulnerability in version 21.2 of the RAS Client. Users should upgrade to version 21.2 or later to remediate this issue. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Classification
- {"confidence":0.95,"severitySource":"cvss-text","classifier":"rss-v2"}
- Article Source
- {"url":"http://www.zerodayinitiative.com/advisories/ZDI-26-556/","fetched":true,"fetchedAt":"2026-08-12T20:03:23.123Z","wordCount":186}
Threat ID: 6a7cd317bf8831d5391487c5
Added to database: 08/12/2026, 20:09:59 UTC
Last enriched: 08/12/2026, 20:11:51 UTC
Last updated: 08/12/2026, 22:41:03 UTC
Views: 2
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