CVE-2026-80302

HIGH
MEDIUM Priority: 0.01 BB Relevance: 43/100
Published: 2026-11-06 Modified: 2026-11-12 First seen: 2026-11-06 Status: active

Attack Surface

Low Complexity No Interaction Conf. Impact Integ. Impact Scope Change

CVSS Vector Breakdown

AV: Local
AC: Low
PR: Low
UI: None
S: Changed
C: High
I: High
A: High

Description

Insufficient isolation in the Avast sandbox file virtualization layer on Windows allows a local, low-privileged attacker executing inside the sandbox to write arbitrary files outside sandbox containment and execute code on the host. The sandbox virtualizes file system operations by intercepting write requests to protected system directories. However, the virtualization implementation fails to properly validate write targets in certain edge cases, allowing writes to bypass the virtualization redirection and reach the actual host file system in protected locations. An attacker can exploit this to overwrite executable files, system libraries, or startup configurations with arbitrary content, leading to code execution with host privileges on subsequent system operations or reboot.

Weakness Classification (2)

Bug Bounty Relevance

43 / 100
✓ Low complexity
✓ No user interaction

CVSS Score

8.8 / 10.0 v3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploitation Probability

0.13%
Raw Score 0.001260
Percentile 2.4%
Date 2026-11-13

EPSS Trend

2026-11-13
0.00126
2026-11-12
0.00126
2026-11-10
0.00169
2026-11-09
0.00169
2026-11-08
0.00169
2026-11-07
0.00169

Intelligence Sources

mitre ref →
nvd ref →