CVE-2026-104892 in Plane
Summary
by MITRE • 10/05/2026
Plane is an open-source project management tool. Prior to 1.4.0, aPITokenLogMiddleware logs API keys in plaintext. This allows someone with low privileges to steal user API keys and further escalate their privileges. This issue is fixed in 1.4.0.
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Analysis
by VulDB Data Team • 10/05/2026
The vulnerability identified within the Plane open-source project management tool prior to version 1.4.0 represents a critical failure in secure logging practices, specifically categorized under CWE-532: Information Exposure Through Log Files. The core technical flaw resides in the PITokenLogMiddleware component, which is responsible for recording API interactions and authentication events. Instead of masking or hashing sensitive credentials such as API keys, this middleware logs them in plaintext within application log files. This design oversight means that any data transmitted during authenticated requests containing valid API tokens is permanently recorded in a readable format on the server filesystem where these logs are stored.
The operational impact of this vulnerability is severe due to its potential for privilege escalation and unauthorized access. Since the logged information includes full, unmasked API keys, an attacker with low-privileged access to the system can exploit this exposure. By gaining read access to the log files through local file inclusion vulnerabilities, insufficient directory permissions, or other lateral movement techniques, a user who should not have administrative capabilities can extract these plaintext credentials. Possession of a valid API key allows the attacker to authenticate as the corresponding user without needing their password, effectively bypassing standard authentication controls and gaining full access to that user's data and functionalities within the Plane application.
This scenario aligns with several tactics in the MITRE ATT&CK framework, particularly T1078: Valid Accounts, where attackers use legitimate credentials to maintain persistence or escalate privileges. It also relates to T1530: Data from Local System, as the attacker is exfiltrating sensitive information directly from the host system's storage. The ability of a low-privileged user to steal high-value secrets like API keys undermines the principle of least privilege and compromises the integrity of the entire application ecosystem, potentially leading to data breaches or further compromise of connected systems that rely on these APIs for integration.
To mitigate this vulnerability, organizations must ensure they are running Plane version 1.4.0 or later, where the logging mechanism has been corrected to prevent plaintext exposure of API keys. For environments still operating on older versions, immediate remediation involves reviewing and restricting file system permissions on log directories to ensure that only authorized administrative processes can read them. Additionally, implementing centralized log management solutions with built-in data loss prevention features can help detect or mask sensitive patterns in logs before they are written permanently. Regular audits of application code for similar logging practices across other middleware components are also recommended to prevent recurrence of information exposure issues.