What is CVE-2024-28199?

CVE-2024-28199 is a high-severity vulnerability in Phlex, classified under Cross-site Scripting. CVSS score: 7.1/10. Published 2024-03-11.

How severe is CVE-2024-28199?

High severity. CVSS v3 base score is 7.1 out of 10.

Is CVE-2024-28199 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Phlex

CVE-2024-28199

phlex is an open source framework for building object-oriented views in Ruby. There is a potential cross-site scripting (XSS) vulnerability that can be exploited via maliciously crafted user data. This was due to improper case-sensitivity in the code that was meant to prevent these attacks. If you render an `<a>` tag with an `href` attribute set to a user-provided link, that link could potentially execute JavaScript when clicked by another user. If you splat user-provided attributes when rendering any HTML tag, malicious event attributes could be included in the output, executing JavaScript when the events are triggered by another user. Patches are available on RubyGems for all 1.x minor versions. Users are advised to upgrade. Users unable to upgrade should consider configuring a content security policy that does not allow `unsafe-inline`.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2024-03-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (46.8th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Phlex — versions 1.1.0, 1.4.0, 1.7.0
Phlex-Ruby Phlex — versions = 1.9.0, >= 1.8.0, < 1.8.2, = 1.7.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

github.com/phlex-ruby/phlex/security/advisories/GHSA-242p-4v39-2v8g (Patch, Vendor Advisory)
github.com/phlex-ruby/phlex/commit/aa50c604cdee1d0ce7ef068a4c66cbd5d43f96a1 (Patch)
developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy (Technical Description)
developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy (Technical Description)

Frequently asked questions

What is CVE-2024-28199?: CVE-2024-28199 is a high-severity vulnerability in Phlex, classified under Cross-site Scripting. CVSS score: 7.1/10. Published 2024-03-11.
How severe is CVE-2024-28199?: High severity. CVSS v3 base score is 7.1 out of 10.
Is CVE-2024-28199 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.