CVE-2026-41544 in QcalAgent
Summary
by MITRE • 10/15/2026
A path traversal vulnerability has been reported to affect QcalAgent. If a remote attacker gains a user account, they can then exploit the vulnerability to read the contents of unexpected files or system data.
We have already fixed the vulnerability in the following version: QcalAgent 1.1.10 and later
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Analysis
by VulDB Data Team • 10/15/2026
The reported security issue within QcalAgent constitutes a path traversal vulnerability that allows for unauthorized access to sensitive file systems when specific authentication conditions are met. This type of flaw typically arises from insufficient validation or sanitization of user-supplied input, specifically regarding file paths requested by the application. In this scenario, an attacker who has already obtained valid credentials can manipulate these inputs to traverse directory boundaries, moving beyond the intended scope of access defined by the software's design. The core technical failure lies in the application's inability to properly canonicalize or restrict path references, enabling the retrieval of files located outside the expected directories. This represents a classic instance where authentication serves as a gatekeeper but fails to enforce strict boundary controls on subsequent resource requests.
From an operational perspective, the impact of this vulnerability is significant for any organization relying on QcalAgent for its functionality. Once an attacker compromises user credentials through phishing, credential stuffing, or other means, they can leverage this path traversal flaw to exfiltrate critical system data and configuration files that were not intended for public or even authenticated consumption. This could include sensitive logs, internal configuration settings containing secrets or API keys, database connection strings, or proprietary source code if accessible via the file system structure. The ability to read unexpected files undermines the confidentiality integrity of the entire environment, potentially serving as a stepping stone for further lateral movement or privilege escalation within the network infrastructure.
This vulnerability aligns with CWE-22: Improper Limitation of a Pathname to a Restricted Directory, which is categorized under the broader class of CWE-78: Improper Neutralization of Special Elements used in an OS Command (OS Command Injection) when file paths are involved in system operations. In terms of offensive security frameworks, this behavior corresponds to ATT&CK technique T1083: File and Directory Discovery, where adversaries explore local systems to gather information for subsequent exploitation phases. The vulnerability highlights the critical importance of implementing strict input validation mechanisms that enforce allow-listing principles rather than relying on block lists or simple string matching. Developers must ensure that all file path inputs are resolved to their absolute paths and verified against a predefined set of allowed directories before any read operations are executed by the operating system.
To mitigate this risk, organizations should immediately upgrade QcalAgent to version 1.1.10 or later, as indicated in the vendor's advisory. This updated release contains the necessary code corrections that likely involve rigorous path normalization and strict directory boundary checks. In addition to applying the patch, administrators should enforce least-privilege principles by ensuring that the service account running QcalAgent has minimal file system permissions, restricted only to the specific directories required for its operation. Regular security audits and static application security testing (SAST) can help identify similar path handling flaws in other components of the software stack, preventing future occurrences of this class of vulnerability across the enterprise environment.