SecuriTricks - CVE-2026-33711

Description

Incus is a system container and virtual machine manager. Incus provides an API to retrieve VM screenshots. That API relies on the use of a temporary file for QEMU to write the screenshot to which is then picked up and sent to the user prior to deletion. As versions prior to 6.23.0 use predictable paths under /tmp for this, an attacker with local access to the system can abuse this mechanism by creating their own symlinks ahead of time. On the vast majority of Linux systems, this will result in a "Permission denied" error when requesting a screenshot. That's because the Linux kernel has a security feature designed to block such attacks, `protected_symlinks`. On the rare systems with this purposefully disabled, it's then possible to trick Incus intro truncating and altering the mode and permissions of arbitrary files on the filesystem, leading to a potential denial of service or possible local privilege escalation. Version 6.23.0 fixes the issue.

Product(s) Impacted

Vendor	Product	Versions
Incus	Incus	<6.23.0

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-61

UNIX Symbolic Link (Symlink) Following

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	incus	incus	<6.23.0	/	/	/	/	/	/	/

References

https://github.com/lxc/incus/security/advisories/GHSA-q9vp-3wcg-8p4x

CVSS Score

4.7 / 10

CVSS Data - 4.0

Attack Vector: LOCAL
Attack Complexity: LOW
Attack Requirements: PRESENT
Privileges Required: LOW
User Interaction: NONE
Scope:
Confidentiality Impact: NONE
Integrity Impact: HIGH
Availability Impact: NONE
Exploit Maturity: PROOF_OF_CONCEPT

CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

View Vector String

Timeline

Published: March 26, 2026, 11:16 p.m.
Last Modified: March 27, 2026, 8:16 p.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

CVE-2026-33711