CVE-2026-40021
Description
A flaw was found in Apache Log4net. An attacker who can influence specific data fields within log messages can exploit this vulnerability. By injecting characters forbidden by the XML 1.0 specification, the attacker can cause an exception during log serialization, leading to the silent loss of log events. This can impair audit trails and hinder the detection of malicious activity, effectively causing a denial of service for logging.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability
Technical Impact: Execute Unauthorized Code or Commands; Read Application Data; Modify Application Data
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