CVE-2025-26803 Phusion Passenger denial of service
An attacker can cause a denial of service in Phusion Passenger by sending a request with an invalid HTTP method.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-26803?
CVE-2025-26803 is a medium-severity denial of service vulnerability in Phusion Passenger, published on 24 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-908
Which versions are affected by CVE-2025-26803?
5 open source packages ship an affected version, including passenger, passenger-apache-module and passenger-nginx-module. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
passenger Bitnami | From 6.0.21 | 6.0.26 |
passenger RubyGems | From 6.0.21 | 6.0.26 |
passenger RubyGems | From 6.0.21 | 6.0.26 |
passenger-apache-module Bitnami | From 6.0.21 | 6.0.26 |
passenger-nginx-module Bitnami | From 6.0.21 | 6.0.26 |
Products include Phusion Passenger.
How do I fix CVE-2025-26803?
Upgrade passenger to 6.0.26 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-26803 being exploited?
There is no known exploitation of CVE-2025-26803 in the wild and no public exploit code.
Other vulnerabilities in Phusion Passenger
- CVE-2018-12026 Phusion Passenger SpawningKit Contains Arbitrary Read/Write Vulnerability
- CVE-2018-12027 Insecure Permissions in Phusion Passenger
- CVE-2018-12028 Incorrect Access Control in Phusion Passenger
- CVE-2016-10345 Phusion Passenger uses a known /tmp filename
- CVE-2012-6135 RubyGems passenger gem allows remote attackers to delete files
Sources
Also known as BIT-passenger-2025-26803, BIT-passenger-apache-module-2025-26803, BIT-passenger-nginx-module-2025-26803, DEBIAN-CVE-2025-26803, GHSA-2cj2-qqxj-5m3r, UBUNTU-CVE-2025-26803.