GHSA-cfjv-5498-mph5
MEDIUMGHSA-cfjv-5498-mph5 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in actionview. O3 Security confirms whether GHSA-cfjv-5498-mph5 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
XSS in Action View
Blast Radius
actionview💎actionviewReal-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
There is a potential Cross-Site Scripting (XSS) vulnerability in Action View's translation helpers. Views that allow the user to control the default (not found) value of the t and translate helpers could be susceptible to XSS attacks.
Impact
When an HTML-unsafe string is passed as the default for a missing translation key named html or ending in _html, the default string is incorrectly marked as HTML-safe and not escaped. Vulnerable code may look like the following examples:
<%# The welcome_html translation is not defined for the current locale: %>
<%= t("welcome_html", default: untrusted_user_controlled_string) %>
<%# Neither the title.html translation nor the missing.html translation is defined for the current locale: %>
<%= t("title.html", default: [:"missing.html", untrusted_user_controlled_string]) %>
Patches
Patched Rails versions, 6.0.3.3 and 5.2.4.4, are available from the normal locations.
The patches have also been applied to the master, 6-0-stable, and 5-2-stable branches on GitHub. If you track any of these branches, you should update to the latest.
To aid users who aren’t able to upgrade immediately, we’ve provided patches for the two supported release series. They are in git-am format and consist of a single changeset.
- 5-2-translate-helper-xss.patch — patch for the 5.2 release series
- 6-0-translate-helper-xss.patch — patch for the 6.0 release series
Please note that only the 5.2 and 6.0 release series are currently supported. Users of earlier, unsupported releases are advised to update as soon as possible, as we cannot provide security fixes for unsupported releases.
Workarounds
Impacted users who can’t upgrade to a patched Rails version can avoid this issue by manually escaping default translations with the html_escape helper (aliased as h):
<%= t("welcome_html", default: h(untrusted_user_controlled_string)) %>
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | actionview | all versions | 5.2.4.4 |
| 💎RubyGems | actionview | ≥ 6.0.0.0&&< 6.0.3.3 | 6.0.3.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for actionview. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update actionview to 5.2.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cfjv-5498-mph5 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 pinpoints whether GHSA-cfjv-5498-mph5 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-cfjv-5498-mph5. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-cfjv-5498-mph5 in your dependencies?
O3 detects GHSA-cfjv-5498-mph5 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.