CVE-2026-112954 in ApostropheCMS
Summary
by MITRE • 10/20/2026
ApostropheCMS is an open-source Node.js content management system. Prior to 4.34.0, a public REST API type that uses publicApiProjection can expose excluded searchable or sortable field information through search membership and sort ordering oracles. Returned fields remain filtered by the projection, so the issue permits targeted inference about hidden values rather than an unrestricted field dump. This issue is fixed in version 4.34.0.
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Analysis
by VulDB Data Team • 10/20/2026
ApostropheCMS represents a widely utilized open-source content management system built on Node.js, designed to facilitate flexible and scalable web development. Within its architecture, the public REST API serves as a critical interface for external applications and clients to interact with stored content. A significant security flaw was identified in versions prior to 4.34.0 concerning how this API handles data projection during search operations. The vulnerability stems from the interaction between the publicApiProjection mechanism and specific query parameters related to sorting and searching, creating a side-channel information leakage vector that undermines intended access controls.
The technical core of this vulnerability lies in the behavior of the public REST API when processing requests that utilize publicApiProjection. While projections are designed to restrict the set of fields returned by an API call, thereby limiting exposure to sensitive data, the implementation failed to adequately sanitize or filter field metadata during search membership and sort ordering operations. Specifically, attackers could exploit this flaw by crafting malicious queries that leverage sorting mechanisms or search filters. By analyzing the system's response patterns, such as error messages, timing differences, or structural changes in the returned JSON payload, an attacker can perform inference attacks to determine whether specific excluded fields exist within a document and potentially deduce their values. This is not a direct dump of all data but rather a targeted method for inferring hidden information through oracle-based techniques.
This type of vulnerability aligns with CWE-209, which describes the generation of an error message that reveals sensitive information to unauthorized actors, as well as CWE-613, concerning insufficient session expiration or lack of proper authentication in API contexts where access controls are bypassed via parameter manipulation. From a tactical perspective, this exploitation technique maps directly to MITRE ATT&CK Technique T1078, Valid Accounts, if the attacker has any level of authenticated access that allows them to issue these queries, and more specifically to information gathering techniques such as OS Commanding or API Abuse where side-channel analysis is used to bypass restrictions. The operational impact involves a compromise of data confidentiality for fields explicitly marked as excluded from public view. Although the projection filter prevents a complete unrestricted dump of all database records, the ability to infer hidden values can still lead to significant security breaches depending on the sensitivity of the inferred data, such as internal identifiers, configuration secrets, or private user attributes.
Mitigation strategies primarily involve upgrading the ApostropheCMS installation to version 4.34.0 or later, where this logic has been corrected to ensure that excluded fields are strictly filtered out during all API operations, including those involving sorting and searching. For organizations unable to immediately patch their systems due to compatibility constraints, defensive measures should include implementing strict rate limiting on search endpoints to mitigate the feasibility of oracle-based inference attacks through timing analysis. Additionally, deploying a Web Application Firewall with rulesets capable of detecting anomalous query patterns associated with blind SQL injection or side-channel probing can provide an additional layer of defense. It is also recommended to audit API configurations to ensure that sensitive fields are not only excluded from projections but also validated against access control lists at the database query level before any sorting or filtering logic is applied, thereby closing the gap between application-level projection and data retrieval mechanisms.