Koodo Reader up to 2.4.6 OPDS handlers books.db cover path traversal

Summaryinfo

A vulnerability described as problematic has been identified in Koodo Reader up to 2.4.6. This vulnerability affects unknown code of the file books.db of the component OPDS handlers. Such manipulation of the argument cover leads to path traversal. This vulnerability is referenced as CVE-2026-121544. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Koodo Reader up to 2.4.6. Affected by this issue is an unknown code block of the file books.db of the component OPDS handlers. The manipulation of the argument cover with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality. CVE summarizes:

Koodo Reader through 2.4.6 contains a path traversal vulnerability in the self-hosted HTTP server's OPDS handlers that allows authenticated attackers to read files outside the upload directory. Attackers can upload a crafted books.db with a cover value containing ../ sequences, then request /opds/cover/{key} to read files accessible to the server process.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-121544 since 11/03/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 11/03/2026). The MITRE ATT&CK project declares the attack technique as T1006.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Name

• Koodo Reader

Version

• 2.4.0
• 2.4.1
• 2.4.2
• 2.4.3
• 2.4.4
• 2.4.5
• 2.4.6

CPE 2.3info

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CPE 2.2info

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