CVE-2026-54183 in Airflow
Summary
by MITRE • 08/12/2026
Apache Airflow's secrets masker hides values stored under sensitive key names when they are displayed in the UI. The masker's recursion-depth limit did not descend into values nested inside a list, tuple, or set beyond that limit, so an Airflow Variable holding such a deeply-nested value was shown unmasked in the Variables UI. The exposure is limited to the UI: any authenticated user who can see the Variable in the UI can already read its full value through the Variables REST API, so this does not disclose data the user could not otherwise obtain — the masking is a shoulder-surfing defense for the UI, not an access-control boundary.
This is an incomplete-fix follow-up to CVE-2026-42358, whose fix made only the dictionary walk unbounded; lists, tuples, and sets beyond the depth limit remained unmasked in the UI. Deployments that applied the CVE-2026-42358 fix should also upgrade to address this residual case. Upgrade to apache-airflow 3.3.1 or later.
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Analysis
by VulDB Data Team • 08/12/2026
Apache Airflow contains a security vulnerability in its secrets masking functionality that represents an incomplete remediation of a previous issue. The vulnerability stems from the masking system's recursion depth limitation which fails to properly traverse nested data structures beyond a specified threshold. While the initial fix for CVE-2026-42358 addressed dictionary traversal recursively, it overlooked the handling of lists, tuples, and sets containing deeply nested sensitive values. This creates a scenario where variables containing complex nested structures exceeding the recursion limit remain unmasked in the user interface, potentially exposing sensitive information through visual inspection.
The technical flaw resides in the masking algorithm's implementation where the recursion depth check only applies to dictionary traversal operations while neglecting other iterable data types that can contain sensitive information. When Airflow processes variables for display in the UI, it recursively examines nested structures to identify and mask sensitive keys, but this recursive descent fails to properly handle lists, tuples, and sets beyond the configured depth limit. This incomplete masking approach creates a security boundary violation where sensitive data remains visible through the interface despite the presence of protective mechanisms.
The operational impact of this vulnerability is primarily limited to user interface exposure rather than direct data leakage through API endpoints. However, it undermines the intended security posture by weakening the shoulder-surfing defense mechanism that protects against casual observation of sensitive information. Authenticated users who can access the Variables UI already possess the capability to retrieve full variable values through the REST API, but the vulnerability removes an additional layer of protection that would normally prevent visual exposure of sensitive data during normal operations.
This vulnerability aligns with CWE-200 (Information Exposure) and CWE-532 (Insertion of Sensitive Information into Log File) categories, representing incomplete security controls where remediation efforts address only partial aspects of a broader issue. The flaw also relates to ATT&CK technique T1566 (Phishing) through the potential exposure of credentials or sensitive configuration data that might be present in nested structures, and T1078 (Valid Accounts) as it leverages existing authenticated access to reveal information that should remain protected. Organizations implementing security controls for information exposure must ensure comprehensive coverage across all data structures rather than partial remediation approaches.
The recommended mitigation strategy requires immediate upgrade to Apache Airflow version 3.3.1 or later, which includes the complete fix addressing recursion handling for all supported iterable data types. This upgrade resolves the incomplete implementation by ensuring consistent recursion depth checking across dictionaries, lists, tuples, and sets. Organizations that previously applied the CVE-2026-42358 patch must verify their deployments have been updated to the complete solution to prevent residual exposure of sensitive information through the user interface. The fix demonstrates the importance of thorough vulnerability remediation that considers all data structures and traversal mechanisms rather than addressing only specific implementation paths.
This vulnerability highlights the complexity of security controls in modern application frameworks where seemingly simple masking functions require comprehensive consideration of all data access patterns. The issue represents a classic example of incomplete security remediation where partial fixes leave residual vulnerabilities, emphasizing the need for thorough testing and validation of security patches across all code paths and data structures. Organizations should implement verification procedures to ensure that security fixes address complete problem domains rather than isolated symptoms, particularly when dealing with information exposure controls that rely on recursive data traversal mechanisms.