CVE-2026-93333 in Vault
Summary
by MITRE • 11/12/2026
Vault's audit devices did not validate the contents of a configured audit log prefix and did not consistently enforce the server-level setting that restricts audit log prefixing. This may allow a privileged operator to inject content into audit logs, potentially leading to forged or misleading audit records. This vulnerability (CVE-2026-93333) is fixed in Vault Community Edition 2.2.2 and Vault Enterprise 2.2.2, 1.21.14, and 1.19.25.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 11/13/2026
The vulnerability identified as CVE-2026-93333 represents a critical integrity failure within the audit logging subsystem of HashiCorp Vault, specifically affecting how configured audit log prefixes are processed and enforced across server-level configurations. Audit logs serve as the primary mechanism for tracking administrative actions, authentication events, and data access patterns, making their reliability paramount for security monitoring, forensic analysis, and regulatory compliance. In this flawed implementation, the software failed to adequately validate the contents of a user-configured audit log prefix string before appending it to log entries. This lack of input sanitization allows an operator with sufficient privileges to inject arbitrary content into the logs rather than just simple alphanumeric identifiers or standard text strings. Furthermore, the vulnerability is compounded by inconsistent enforcement of server-level settings that are designed to restrict or control how these prefixes are applied, creating a discrepancy between intended policy and actual behavior depending on specific configuration states or operational contexts.
From a technical perspective, this flaw aligns with CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component, as the system fails to neutralize special elements within the audit log prefix before writing them to the output stream. The core issue lies in the absence of strict validation logic that would ensure only expected character sets or patterns are permitted in the prefix field. When an attacker with privileged access configures a maliciously crafted prefix containing control characters, escape sequences, or structured data mimicking legitimate log entries, these injected strings are written directly into the audit trail without modification. This capability effectively breaks the chain of trust for the audit logs, as subsequent analysis tools and security information and event management systems may interpret the injected content as genuine system events rather than metadata artifacts.
The operational impact of this vulnerability is severe due to its potential to facilitate sophisticated evasion techniques and data manipulation. An attacker who gains privileged access can use this flaw to forge or misleadingly alter audit records, thereby obscuring their own malicious activities such as unauthorized key extraction, policy modification, or secret deletion. By injecting false positive events or masking real attacks with noise, the adversary can confuse security analysts and automated detection systems, leading to delayed incident response or complete failure of forensic investigations. This directly undermines the principle of non-repudiation, which is essential for accountability in enterprise environments. The inconsistency in enforcing server-level restrictions further exacerbates the risk, as administrators may believe their global policies are being applied uniformly when they are not, creating blind spots where malicious logging behavior can persist undetected across different nodes or configuration states within a Vault cluster.
This vulnerability maps to several techniques within the MITRE ATT&CK framework, particularly T1070 Indicator Removal on Host and T1562 Impair Defenses. The ability to inject content into logs allows an attacker to impair defensive capabilities by confusing log analysis tools and potentially causing them to discard or misclassify critical alerts. Additionally, it relates to T1498 Network Denial of Service if the injection is used to bloat logs excessively, though the primary threat here is integrity compromise rather than availability disruption. The lack of validation also touches upon CWE-20 Improper Input Validation, highlighting a fundamental gap in how user-supplied configuration data is handled before being committed to persistent storage or output streams that feed into security monitoring pipelines.
Mitigation for this vulnerability requires immediate patching to the fixed versions provided by HashiCorp. Organizations running Vault Community Edition must upgrade to version 2.2.2, while those using Vault Enterprise should update to either version 1.19.25, 1.21.14, or 2.2.2 depending on their specific edition and support lifecycle requirements. Until patches are applied, administrators should rigorously review all audit log prefix configurations to ensure they contain only safe, alphanumeric characters and avoid any special symbols that could be interpreted as control codes by downstream logging systems. It is also advisable to implement external monitoring solutions that can detect anomalies in log volume or format deviations, providing an additional layer of defense against potential exploitation attempts while the internal validation flaws remain unpatched. Regular audits of audit logs for unexpected patterns or inconsistencies should become a standard operational procedure to identify any signs of prior exploitation before the vulnerability is fully remediated.