Phusion Passenger up to 6.0.25 HTTP Parser uninitialized resource

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Phusion Passenger up to 6.0.25. This affects an unknown function of the component HTTP Parser. This manipulation causes uninitialized resource. The identification of this vulnerability is CVE-2025-26803. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Phusion Passenger up to 6.0.25 and classified as problematic. Affected by this vulnerability is an unknown functionality of the component HTTP Parser. The manipulation with an unknown input leads to a uninitialized resource vulnerability. The CWE definition for the vulnerability is CWE-908. The product uses or accesses a resource that has not been initialized. As an impact it is known to affect availability. The summary by CVE is:

The http parser in Phusion Passenger 6.0.21 through 6.0.25 before 6.0.26 allows a denial of service during parsing of a request with an invalid HTTP method.

The advisory is shared at phusionpassenger.com. This vulnerability is known as CVE-2025-26803 since 02/14/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

Upgrading to version 6.0.26 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch bb15591646687064ab2d578d5f9660b2a4168017 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.

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

Productinfo

Vendor

• Phusion

Name

• Passenger

Version

• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3
• 6.0.4
• 6.0.5
• 6.0.6
• 6.0.7
• 6.0.8
• 6.0.9
• 6.0.10
• 6.0.11
• 6.0.12
• 6.0.13
• 6.0.14
• 6.0.15
• 6.0.16
• 6.0.17
• 6.0.18
• 6.0.19
• 6.0.20
• 6.0.21
• 6.0.22
• 6.0.23
• 6.0.24
• 6.0.25

License

• open-source

Website

• Product: https://github.com/phusion/passenger/

CPE 2.3info

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CPE 2.2info

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

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