How severe is CVE-2024-26143?

CVE-2024-26143 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2024-26143?

CVE-2024-26143 affects the following packages: actionpack (RubyGems), actionpack (RubyGems), rails (RubyGems), rails (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2024-26143?

Update actionpack to 7.0.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-26143 is resolved across your whole dependency graph.

How do I detect CVE-2024-26143 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for actionpack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2024-26143 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2024-26143 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-26143 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2024-26143?

CVE-2024-26143 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 64th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2024-26143?

CVE-2024-26143 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2024-26143 published, and has it been updated?

CVE-2024-26143 was published on February 27, 2024 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎

💎 RubyGems

Not in CISA KEV

MEDIUM severity

CVE-2024-26143 — actionpack

MEDIUMFix: rails/rails@4c83b33

CVE-2024-26143 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in actionpack. A fix is available for actionpack — see the affected versions and patch details below.

Rails Possible XSS Vulnerability in Action Controller

Also known asBIT-rails-2024-26143GHSA-9822-6m93-xqf4

Published

Feb 27, 2024

Updated

Oct 28, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-26143.

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs64th percentile — riskier than 64% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 pkgs affected

💎actionpack💎actionpack💎rails💎rails

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

Possible XSS Vulnerability in Action Controller

There is a possible XSS vulnerability when using the translation helpers (translate, t, etc) in Action Controller. This vulnerability has been assigned the CVE identifier CVE-2024-26143.

Versions Affected: >= 7.0.0. Not affected: < 7.0.0 Fixed Versions: 7.1.3.1, 7.0.8.1

Impact

Applications using translation methods like translate, or t on a controller, with a key ending in "_html", a :default key which contains untrusted user input, and the resulting string is used in a view, may be susceptible to an XSS vulnerability.

For example, impacted code will look something like this:

class ArticlesController < ApplicationController
  def show  
    @message = t("message_html", default: untrusted_input)
    # The `show` template displays the contents of `@message`
  end
end

To reiterate the pre-conditions, applications must:

Use a translation function from a controller (i.e. not I18n.t, or t from a view)
Use a key that ends in _html
Use a default value where the default value is untrusted and unescaped input
Send the text to the victim (whether that's part of a template, or a render call)

All users running an affected release should either upgrade or use one of the workarounds immediately.

Releases

The fixed releases are available at the normal locations.

Workarounds

There are no feasible workarounds for this issue.

Patches

To aid users who aren't able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset.

7-0-translate-xss.patch - Patch for 7.0 series
7-1-translate-xss.patch - Patch for 7.1 series

Credits

Thanks to ooooooo_q for the patch and fix!

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`actionpack`	≥ 7.0.0&&< 7.0.8.1	7.0.8.1`bundle update actionpack --conservative`
💎RubyGems	`actionpack`	≥ 7.1.0&&< 7.1.3.1	7.1.3.1`bundle update actionpack --conservative`
💎RubyGems	`rails`	≥ 7.0.0&&< 7.0.8.1	7.0.8.1`bundle update rails --conservative`
💎RubyGems	`rails`	≥ 7.1.0&&< 7.1.3.1	7.1.3.1`bundle update rails --conservative`

Affected Products

1 product · 2 configurations

Application

railsrubyonrails

≥ 7.1.0 && < 7.1.3.1

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for actionpack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update actionpack to 7.0.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-26143 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

# Possible XSS Vulnerability in Action Controller There is a possible XSS vulnerability when using the translation helpers (`translate`, `t`, etc) in Action Controller. This vulnerability has been assigned the CVE identifier CVE-2024-26143. Versions Affected: >= 7.0.0. Not affected: < 7.0.0 Fixed Versions: 7.1.3.1, 7.0.8.1 Impact ------ Applications using translation methods like `translate`, or `t` on a controller, with a key ending in "_html", a `:default` key which contains untrusted user input, and the resulting string is used in a view, may be susceptible to an XSS vulnerabi