---
title: "CVE-2019-5420: Rails https://github.com/rails/rails… | CubePath"
description: "A remote code execution vulnerability in development mode Rails <5.2.2.1, <6.0.0.beta3 can allow an attacker to guess the automatically generated…"
language: en
source: https://cubepath.com/security/cve/CVE-2019-5420
---

# CVE-2019-5420: Rails https://github.com/rails/rails… | CubePath

## Description

A remote code execution vulnerability in development mode Rails <5.2.2.1, <6.0.0.beta3 can allow an attacker to guess the automatically generated development mode secret token. This secret token can be used in combination with other Rails internals to escalate to a remote code execution exploit.

Official description from the CVE record, published by hackerone. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2019-5420)

## Key data

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.89330 (89.3% probability)

Percentile

99.8%

Scores of

Nov 10, 2026

Model

v2026.06.15

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-77](https://cwe.mitre.org/data/definitions/77.html) Improper Neutralization of Special Elements used in a Command

## Affected products

Products listed in the CVE record, as the CNA published them.

- Rails https://github.com/rails/rails

  - affected: 5.2.2.1
  - affected: 6.0.0.beta3

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have…](https://weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have-been-released/)
- [groups.google.com/forum](https://groups.google.com/forum/#%21topic/rubyonrails-security/IsQKvDqZdKw)
- [packetstormsecurity.com/files/152704/Ruby-On-Rails-DoubleTa…](http://packetstormsecurity.com/files/152704/Ruby-On-Rails-DoubleTap-Development-Mode-secret%5Fkey%5Fbase-Remote-Code-Execution.html)
- [46785](https://www.exploit-db.com/exploits/46785/)  (exploit-db.com) exploit
- [FEDORA-2019-1cfe24db5c](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/)  (lists.fedoraproject.org) vendor-advisory

## Timeline

1. ID reserved Jan 4, 2019
2. Record published Mar 27, 2019
3. Record last updated Aug 4, 2024

## Look up another CVE

## About CubePath

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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 20:01 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)