CVE-2019-18978

5.3 MEDIUM 2% exploit odds Fix listed

What it is

An issue was discovered in the rack-cors (aka Rack CORS Middleware) gem before 1.0.4 for Ruby. It allows ../ directory traversal to access private resources because resource matching does not ensure that pathnames are in a canonical format.

At a glance

Exploitability: Can be exploited over the network without logging in. Limited direct impact.
Exploit odds: 2.5% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2019-11-14 21:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 02:25 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 2.5% in the next 30 days (EPSS).
Severity: 5.3 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2019-11-14 21:15 UTC
Last modified: 2026-06-17 02:25 UTC
Exploit probability: 2.5% · EPSS, next 30 days
Weakness: CWE-22 · Path traversal
Record status: Modified

Affected

rack-cors Project rack-cors < 1.0.4
Debian Linux 8.0
Debian Linux 9.0
Debian Linux 10.0
Canonical Ubuntu Linux 16.04

Attack profile CVSS 3.1 · 5.3

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2019-18978.md and follow it. Check whether this project is affected by CVE-2019-18978. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record