Qubes OS up to 4.3.21 File Copy Agent qfile-dom0-agent.c system os command injection

Summaryinfo

A vulnerability, which was classified as very critical, was found in Qubes OS up to 4.3.21. The impacted element is the function system of the file core-admin-linux/file-copy-vm/qfile-dom0-agent.c of the component File Copy Agent. The manipulation results in os command injection. This vulnerability is known as CVE-2026-82636. Attacking locally is a requirement. No exploit is available.

Detailsinfo

A vulnerability was found in Qubes OS up to 4.3.21. It has been classified as very critical. Affected is the function system of the file core-admin-linux/file-copy-vm/qfile-dom0-agent.c of the component File Copy Agent. The manipulation with an unknown input leads to a os command injection vulnerability. CWE is classifying the issue as CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Qubes OS before qubes-core-dom0-linux 4.3.22 allows OS command injection during a qvm-copy-to-vm call from dom0 to an attacker-controlled qube, because the "system" library function is used to process an error message that may have shell metacharacters. This occurs in core-admin-linux/file-copy-vm/qfile-dom0-agent.c.

The advisory is shared for download at qubes-os.org. This vulnerability is traded as CVE-2026-82636 since 08/30/2026. The exploitability is told to be easy. The attack needs to be approached locally. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/30/2026). The MITRE ATT&CK project declares the attack technique as T1202.

Upgrading to version 4.3.22 eliminates this vulnerability.

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Productinfo

Name

• Qubes OS

Version

• 4.3.0
• 4.3.1
• 4.3.2
• 4.3.3
• 4.3.4
• 4.3.5
• 4.3.6
• 4.3.7
• 4.3.8
• 4.3.9
• 4.3.10
• 4.3.11
• 4.3.12
• 4.3.13
• 4.3.14
• 4.3.15
• 4.3.16
• 4.3.17
• 4.3.18
• 4.3.19
• 4.3.20
• 4.3.21

CPE 2.3info

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CPE 2.2info

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