PyPI: uvicorn

CVE-2020-7694

Safety vulnerability ID: SFTY-20200727-49565

Safety legacy ID: pyup.io-38664

The request logger provided by Uvicorn prior to version 0.11.7 is vulnerable to ASNI escape sequence injection. Whenever any HTTP request is received, the default behaviour of uvicorn is to log its details to either the console or a log file. When attackers request crafted URLs with percent-encoded escape sequences, the logging component will log the URL after it's been processed with urllib.parse.unquote, therefore converting any percent-encoded characters into their single-character equivalent, which can have special meaning in terminal emulators. By requesting URLs with crafted paths, attackers can: * Pollute uvicorn's access logs, therefore jeopardising the integrity of such files. * Use ANSI sequence codes to attempt to interact with the terminal emulator that's displaying the logs (either in real time or from a file). See: CVE-2020-7694.

Created at: May 21, 2026Updated at: May 21, 2026

Overview

Log injection in uvicorn

Advisory

The request logger provided by Uvicorn prior to version 0.11.7 is vulnerable to ASNI escape sequence injection. Whenever any HTTP request is received, the default behaviour of uvicorn is to log its details to either the console or a log file. When attackers request crafted URLs with percent-encoded escape sequences, the logging component will log the URL after it's been processed with urllib.parse.unquote, therefore converting any percent-encoded characters into their single-character equivalent, which can have special meaning in terminal emulators. By requesting URLs with crafted paths, attackers can: * Pollute uvicorn's access logs, therefore jeopardising the integrity of such files. * Use ANSI sequence codes to attempt to interact with the terminal emulator that's displaying the logs (either in real time or from a file). See: CVE-2020-7694.

Affected Package

Affecting uvicorn package, versions
<0.11.7

Also affects

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How to Fix

Upgrade
uvicorn
to
0.11.7
or higher.

Mitigation and Workarounds

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Vulnerable Functions

Functions linked to known vulnerabilities.

Vulnerable function data is available for Enterprise customers

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Safety

Verified by Safety

Our Cybersecurity Intelligence Team reviewed this vulnerability. We combine public data with our own research to find issues not yet reported to public sources.

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