CVE-2026-86544 in knowns
Summary
by MITRE • 09/08/2026
knowns versions before 0.30.0 contain an authorization bypass vulnerability where mutating code actions are incorrectly classified as read-only operations. Attackers with read-restricted sessions can exploit code.replace to modify permission configurations and escalate privileges on subsequent calls.
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Analysis
by VulDB Data Team • 09/08/2026
The identified security flaw represents a critical authorization bypass within the software ecosystem prior version 0.30.0, stemming from an incorrect classification of mutating code actions as read-only operations. This fundamental logic error in the access control mechanism allows attackers to circumvent intended restrictions by exploiting specific API methods designed for data modification. Specifically, the vulnerability centers on the misuse of the code.replace function, which is typically expected to perform non-destructive or informational updates but is instead leveraged to alter critical permission configurations. By treating these mutating operations as benign read-only activities, the system fails to enforce proper authentication and authorization checks that would normally restrict such changes to privileged users only.
From a technical perspective, this vulnerability aligns with CWE-269, which denotes Improper Privilege Control, where an actor is able to elevate their privileges or access resources beyond what was intended by the security architecture. The exploitation vector relies on session-based restrictions; attackers who possess read-restricted sessions can manipulate internal state variables through the code.replace method. This manipulation effectively rewrites permission configurations in memory or persistent storage without triggering the necessary administrative validation steps. Consequently, subsequent calls made under these modified contexts are granted elevated privileges, allowing the attacker to perform actions that were originally prohibited by their initial role assignment.
The operational impact of this vulnerability is severe, as it enables direct privilege escalation from a low-privileged user account to an administrator or higher-level access tier. Once permission configurations are altered, the compromised session can execute administrative commands, modify system settings, and potentially exfiltrate sensitive data that was previously protected by role-based access controls. This undermines the integrity of the entire security model, as trust in session boundaries is broken. Attackers can maintain persistent access by ensuring their elevated privileges remain active across sessions if the configuration changes are persisted, leading to long-term compromise of the application environment and potential lateral movement within connected systems.
In terms of threat modeling, this behavior corresponds to ATT&CK technique T1078, Valid Accounts, specifically involving privilege escalation through misconfigured permissions or exploitation of logic flaws in access control lists. The attacker leverages valid but restricted credentials to bypass security controls, demonstrating a failure in the principle of least privilege enforcement during state mutation operations. This type of vulnerability is particularly dangerous because it does not require external exploits like buffer overflows; instead, it relies on logical errors that are often harder to detect through standard static analysis tools unless specifically targeted at authorization logic paths.
To mitigate this risk, immediate action must be taken by upgrading the software to version 0.30.0 or later, where these classification issues have been resolved and proper validation checks for mutating operations have been implemented. For systems that cannot be immediately upgraded, a temporary workaround involves implementing strict input validation on all code.replace calls to ensure they are only processed when authenticated as an administrator role. Additionally, enabling comprehensive audit logging for permission configuration changes can help detect exploitation attempts in real-time. Security teams should also review their access control policies to ensure that read-only sessions cannot interact with any endpoints or functions capable of modifying system state, thereby enforcing a stricter separation between reading and writing operations at the architectural level.