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
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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-26143 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
actionpack💎actionpack💎rails💎railsReal-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
tfrom 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
rendercall)
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
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | actionpack | ≥ 7.0.0&&< 7.0.8.1 | 7.0.8.1bundle update actionpack --conservative |
| 💎RubyGems | actionpack | ≥ 7.1.0&&< 7.1.3.1 | 7.1.3.1bundle update actionpack --conservative |
| 💎RubyGems | rails | ≥ 7.0.0&&< 7.0.8.1 | 7.0.8.1bundle update rails --conservative |
| 💎RubyGems | rails | ≥ 7.1.0&&< 7.1.3.1 | 7.1.3.1bundle update rails --conservative |
Detection & mitigation playbook
Open-source dependencyDetect
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
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-26143 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-26143. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-26143 in your dependencies?
O3 Security finds CVE-2024-26143 across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.