CVE-2026-22041 Overview
CVE-2026-22041 is a Type Confusion vulnerability affecting the Logging Redactor Python library, a tool designed to redact sensitive data in logs based on regex patterns and dictionary keys. Prior to version 0.0.6, the library incorrectly converts non-string types into string types, leading to type errors when processing %d format conversions in logging statements. This behavior can cause unexpected application errors and potentially disrupt logging functionality in affected applications.
Critical Impact
Applications using Logging Redactor versions prior to 0.0.6 may experience type errors during log processing, potentially causing logging failures or application instability when non-string data types are passed through the redaction pipeline.
Affected Products
- Logging Redactor Python library versions prior to 0.0.6
Discovery Timeline
- 2026-01-08 - CVE CVE-2026-22041 published to NVD
- 2026-01-08 - Last updated in NVD database
Technical Details for CVE-2026-22041
Vulnerability Analysis
This vulnerability falls under CWE-704 (Incorrect Type Conversion or Cast). The Logging Redactor library is designed to intercept log messages and redact sensitive information based on configurable regex patterns or dictionary keys. However, the implementation has a flaw in how it handles data type conversions during the redaction process.
When the library processes log messages containing format specifiers like %d (which expects integer values), it incorrectly converts all incoming data to string types before processing. This conversion causes a type mismatch when Python's logging system attempts to apply the integer format specifier to what is now a string value, resulting in a TypeError.
The vulnerability requires local access to exploit, as an attacker would need the ability to control log inputs or modify application code. While the integrity impact is limited, the vulnerability can disrupt logging functionality in applications that rely on numeric format specifiers in their log messages.
Root Cause
The root cause is improper type handling in the Logging Redactor's message processing pipeline. The library performs an unconditional type conversion to string on all log arguments before applying redaction rules, without preserving the original data types needed for proper format string processing. This breaks Python's standard logging format string behavior where %d expects an integer argument.
Attack Vector
The attack vector is local, requiring an attacker to have access to influence log inputs within an application using the vulnerable library. Exploitation involves sending log messages with non-string arguments (such as integers) that use corresponding format specifiers. When the Logging Redactor processes these messages, the type conversion causes the logging call to fail.
The vulnerability mechanism can be described as follows: when a logging statement like logger.info("User ID: %d", user_id) is processed through the Logging Redactor, the integer user_id value is converted to a string. When Python's logging formatter then attempts to apply the %d specifier to this string value, a TypeError is raised. See the GitHub Security Advisory GHSA-rvjx-cfjh-5mc9 for additional technical details.
Detection Methods for CVE-2026-22041
Indicators of Compromise
- Unexpected TypeError exceptions in application logs related to format string processing
- Failed log entries with error messages indicating type mismatches in format specifiers
- Application logging failures when using %d, %i, or other non-string format specifiers with Logging Redactor
Detection Strategies
- Review Python dependency manifests (requirements.txt, setup.py, pyproject.toml) for loggingredactor versions below 0.0.6
- Implement automated dependency scanning using tools like pip-audit or safety to identify vulnerable package versions
- Monitor application exception logs for TypeError stack traces originating from logging redaction operations
Monitoring Recommendations
- Set up alerting for type-related exceptions in logging pipelines
- Implement centralized log aggregation to detect patterns of logging failures
- Use Python application performance monitoring (APM) tools to track exception rates in logging code paths
How to Mitigate CVE-2026-22041
Immediate Actions Required
- Upgrade Logging Redactor to version 0.0.6 or later immediately
- Review applications using the library to identify any that may be affected by the type conversion bug
- Test logging functionality after upgrade to confirm proper format string handling
Patch Information
The vulnerability has been patched in Logging Redactor version 0.0.6. Users should upgrade to this version or later to remediate the issue. The fix is available through the standard Python package repository or directly from the GitHub Release 0.0.6.
Additional details about the vulnerability and fix can be found in the GitHub Issue #7 and the GitHub Security Advisory GHSA-rvjx-cfjh-5mc9.
Workarounds
- No official workarounds are available for this vulnerability
- As a temporary measure, avoid using non-string format specifiers (%d, %i, %f) in logging statements that pass through the Logging Redactor
- Convert all log arguments to strings explicitly before logging to bypass the type conversion issue until upgrade is possible
# Upgrade to patched version
pip install loggingredactor>=0.0.6
# Verify installed version
pip show loggingredactor | grep Version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
