Incorrect Access Control in Phusion Passenger

published 2018-06-17 8 y ago modified 2026-06-17 4 mo ago also GHSA-jjhj-8gx7-x836 , EUVD-2022-4386

cvss: 7.8; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.9%; EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits: 0; none known

An Incorrect Access Control vulnerability in SpawningKit in Phusion Passenger 5.3.x before 5.3.2 allows a Passenger-managed malicious application, upon spawning a child process, to report an arbitrary different PID back to Passenger's process manager. If the malicious application then generates an error, it would cause Passenger's process manager to kill said reported arbitrary PID.

Patch / fix

fixed in 2 links 1

rubygems passenger 5.3.2
phusion passenger 5.3.2

github.com/phusion/passenger@1e7c82d commit

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-12028 updated 2025-11-21 cvss 4.7

passenger: Improper access control in SpawningKit can allow malicious child processes to kill arbitrary processes

Red Hat Ceph Storage 1.3 rubygem-passenger Red Hat Satellite 6 mod_passenger, rubygem-passenger, rubygem-passenger-native, rubygem-passenger-native-libs Red Hat Update Infrastructure 3 for Cloud Providers rubygem-passenger
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.89% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.0	7.8	CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	2.0	6.8	AV:N/AC:M/Au:N/C:P/I:P/A:P
GitHub	3.0	7.8	CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
rubygems	passenger	>=5.3.0, <5.3.2	5.3.2

Classification

Weakness

CWE-732 Incorrect Permission Assignment for Critical Resource

References

github.com /phusion/passenger/commit/1e7c82deb4901c438f583737d8c9f2aac264737c
web
security.gentoo.org /glsa/201807-02
vendor-advisory, web, third-party-advisory
blog.phusion.nl /passenger-5-3-2
web, mitigation, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2018-12028
advisory
github.com /phusion/passenger
package
github.com /rubysec/ruby-advisory-db/blob/master/gems/passenger/CVE-2018-12028.yml
web

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary