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Fencer Vulns
critical 9.8

CVE-2018-12026 json

Phusion Passenger SpawningKit Contains Arbitrary Read/Write Vulnerability

published 2018-06-17 8 y ago modified 2026-06-17 4 mo ago also GHSA-7cv3-gvmc-8mq5 , EUVD-2022-2976

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

During the spawning of a malicious Passenger-managed application, SpawningKit in Phusion Passenger 5.3.x before 5.3.2 allows such applications to replace key files or directories in the spawning communication directory with symlinks. This then could result in arbitrary reads and writes, which in turn can result in information disclosure and privilege escalation.

Patch / fix

  • rubygems passenger 5.3.2
  • phusion passenger 5.3.2

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-2018-12026 updated cvss 7.1

passenger: SpawningKit allows malicious applications to replace files and directories allowing for arbitrary reads and writes

  • 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

1.92% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/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-59 Improper Link Resolution Before File Access

References

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.