CVE-2026-87798: CWE-59 Improper link resolution before file access ('link following') in Canonical LXD
Improper link resolution in the recursive file pull feature of the LXD CLI client in Canonical LXD versions 4.0.2 up to 6.9 (fixed in 4.0.14, 5.0.10 and 5.21.8) on Linux allows an attacker with root access inside a virtual machine to write attacker-controlled files or directory trees to arbitrary paths on the client host, with the operator's privileges. The attacker does this by using a modified lxd-agent that returns inconsistent SFTP directory listings and Lstat results.
AI Analysis
Technical Summary
CVE-2026-87798 is a CWE-59 improper link resolution vulnerability in the recursive file pull feature of the LXD CLI client in Canonical LXD. It allows an attacker with root access inside a VM to write attacker-controlled files or directory trees to arbitrary paths on the client host by exploiting inconsistent SFTP directory listings and Lstat results returned by a modified lxd-agent. The vulnerability affects multiple LXD versions from 4.0.2 up to but excluding 4.0.14, 5.0.0 up to but excluding 5.0.10, 5.21.0 up to but excluding 5.21.8, and 6.0 up to but excluding 6.9. Fixes have been released in versions 4.0.14, 5.0.10, and 5.21.8.
Potential Impact
An attacker with root access inside a virtual machine can leverage this vulnerability to write files or directories to arbitrary locations on the host system with the privileges of the operator running the LXD client. This could lead to unauthorized modification of host files and potential privilege escalation. The vulnerability does not affect confidentiality or availability but impacts integrity.
Mitigation Recommendations
Upgrade affected LXD CLI client versions to 4.0.14, 5.0.10, 5.21.8, or later where the issue is fixed. No other mitigation or temporary workaround is indicated. Patch status is confirmed fixed in these versions.
CVE-2026-87798: CWE-59 Improper link resolution before file access ('link following') in Canonical LXD
Description
Improper link resolution in the recursive file pull feature of the LXD CLI client in Canonical LXD versions 4.0.2 up to 6.9 (fixed in 4.0.14, 5.0.10 and 5.21.8) on Linux allows an attacker with root access inside a virtual machine to write attacker-controlled files or directory trees to arbitrary paths on the client host, with the operator's privileges. The attacker does this by using a modified lxd-agent that returns inconsistent SFTP directory listings and Lstat results.
CVSS v3.1
Score 5.8medium
Affected software
Canonical
LXD
pkg:github/LXDRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-87798 is a CWE-59 improper link resolution vulnerability in the recursive file pull feature of the LXD CLI client in Canonical LXD. It allows an attacker with root access inside a VM to write attacker-controlled files or directory trees to arbitrary paths on the client host by exploiting inconsistent SFTP directory listings and Lstat results returned by a modified lxd-agent. The vulnerability affects multiple LXD versions from 4.0.2 up to but excluding 4.0.14, 5.0.0 up to but excluding 5.0.10, 5.21.0 up to but excluding 5.21.8, and 6.0 up to but excluding 6.9. Fixes have been released in versions 4.0.14, 5.0.10, and 5.21.8.
Potential Impact
An attacker with root access inside a virtual machine can leverage this vulnerability to write files or directories to arbitrary locations on the host system with the privileges of the operator running the LXD client. This could lead to unauthorized modification of host files and potential privilege escalation. The vulnerability does not affect confidentiality or availability but impacts integrity.
Mitigation Recommendations
Upgrade affected LXD CLI client versions to 4.0.14, 5.0.10, 5.21.8, or later where the issue is fixed. No other mitigation or temporary workaround is indicated. Patch status is confirmed fixed in these versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- canonical
- Date Reserved
- 2026-09-09T10:00:46.383Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aba6ca0f7a7c54106b9890b
Added to database: 09/28/2026, 13:33:20 UTC
Last enriched: 09/28/2026, 13:48:27 UTC
Last updated: 09/29/2026, 01:57:22 UTC
Views: 15
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