py-pdf pypdf up to 6.5.x Root Object Size resource consumption

Summaryinfo

A vulnerability identified as problematic has been detected in py-pdf pypdf up to 6.5.x. This issue affects some unknown processing of the component Root Object Handler. Performing a manipulation of the argument Size results in resource consumption. This vulnerability is reported as CVE-2026-22690. The attack is possible to be carried out remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in py-pdf pypdf up to 6.5.x. It has been classified as problematic. This affects some unknown functionality of the component Root Object Handler. The manipulation of the argument Size with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. The summary by CVE is:

pypdf is a free and open-source pure-python PDF library. Prior to version 6.6.0, pypdf has possible long runtimes for missing /Root object with large /Size values. An attacker who uses this vulnerability can craft a PDF which leads to possibly long runtimes for actually invalid files. This can be achieved by omitting the /Root entry in the trailer, while using a rather large /Size value. Only the non-strict reading mode is affected. This issue has been patched in version 6.6.0.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-22690 since 01/08/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 282554 (Linux Distros Unpatched Vulnerability : CVE-2026-22690), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 294165726b646bb7799be1cc787f593f2fdbcf45 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (282554), EUVD (EUVD-2026-1878) and CERT Bund (WID-SEC-2026-1730). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Xerox FreeFlow Print Server

Productinfo

Vendor

• py-pdf

Name

• pypdf

Version

• 6.0
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5

License

• open-source

Website

• Product: https://github.com/py-pdf/pypdf/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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