CVE-2026-26100 is a vulnerability identified in Owl opds version 2.2.0.4, categorized under CWE-732, which pertains to incorrect permission assignment for critical resources. This flaw allows an attacker with low-level privileges (PR:L) and local access (AV:L) to perform unauthorized file manipulation through specially crafted network requests. The vulnerability does not require user interaction (UI:N) and does not affect confidentiality or availability but has a high impact on integrity (VI:H). The CVSS 4.0 score of 6.8 reflects a medium severity rating. The core issue is that critical resources within Owl opds are assigned permissions that are too permissive, enabling attackers to modify files they should not have access to. This can lead to unauthorized changes in application behavior or data corruption. The vulnerability is exploitable without authentication tokens or elevated privileges beyond low-level access, making it a significant risk in environments where multiple users have limited access to the system. No patches or known exploits are currently available, indicating the need for proactive mitigation. The vulnerability was published on February 20, 2026, and is currently in a published state with no known exploits in the wild.

The primary impact of CVE-2026-26100 is on the integrity of systems running Owl opds 2.2.0.4. Attackers with low privileges can manipulate files, potentially altering application behavior, injecting malicious code, or corrupting data. This can lead to unauthorized changes that may disrupt service or compromise the trustworthiness of the system. Since the vulnerability requires local access with low privileges, insider threats or compromised low-privilege accounts pose a significant risk. The lack of impact on confidentiality and availability reduces the risk of data leaks or denial of service, but the integrity compromise can still have severe operational consequences. Organizations relying on Owl opds for critical functions may face operational disruptions or require extensive remediation efforts if exploited. The absence of known exploits currently provides a window for defensive measures but also indicates that attackers may develop exploits in the future.

1. Restrict access to Owl opds services to trusted users only, minimizing the number of accounts with local access. 2. Implement strict network segmentation and firewall rules to limit exposure of Owl opds to untrusted networks. 3. Monitor file system changes and network traffic for unusual or unauthorized file manipulation attempts targeting Owl opds resources. 4. Apply the principle of least privilege rigorously, ensuring users and processes have only the permissions necessary to perform their tasks. 5. Regularly audit permissions on critical resources within Owl opds to detect and correct overly permissive settings. 6. Stay alert for official patches or updates from the Owl vendor and apply them promptly once available. 7. Consider deploying host-based intrusion detection systems (HIDS) to detect anomalous file modifications. 8. Educate administrators and users about the risks of local privilege misuse and enforce strong authentication and access controls.