In aiohttp, compressed files as symlinks are not protected from path traversal
At a glance
Severity
MEDIUM 4.8
EPSS
EPSS 0.65 % · percentile 51 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Analyzed
Description
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. In versions on the 3.10 branch prior to version 3.10.2, static routes which contain files with compressed variants (`.gz` or `.br` extension) are vulnerable to path traversal outside the root directory if those variants are symbolic links. The server protects static routes from path traversal outside the root directory when `follow_symlinks=False` (default). It does this by resolving the requested URL to an absolute path and then checking that path relative to the root. However, these checks are not performed when looking for compressed variants in the `FileResponse` class, and symbolic links are then automatically followed when performing the `Path.stat()` and `Path.open()` to send the file. Version 3.10.2 contains a patch for the issue.
