What is CVE-2023-28120?

CVE-2023-28120 is a medium-severity vulnerability in Rails Activesupport, classified under Cross-site Scripting. CVSS score: 5.3/10. Published 2025-01-09.

How severe is CVE-2023-28120?

Medium severity. CVSS v3 base score is 5.3 out of 10.

XSS in Rails Activesupport

CVE-2023-28120

There is a vulnerability in ActiveSupport if the new bytesplice method is called on a SafeBuffer with untrusted user input.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2025-01-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.009 (58.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 58.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Rails Activesupport — versions 7.0.4.3, 6.1.7.3

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2023-28120?: CVE-2023-28120 is a medium-severity vulnerability in Rails Activesupport, classified under Cross-site Scripting. CVSS score: 5.3/10. Published 2025-01-09.
How severe is CVE-2023-28120?: Medium severity. CVSS v3 base score is 5.3 out of 10.