GHSA-pj73-v5mw-pm9j
MEDIUMPossible XSS Security Vulnerability in SafeBuffer#bytesplice
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.
Blast Radius
activesupport💎activesupportReal-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 vulnerability in ActiveSupport if the new bytesplice method is called on a SafeBuffer with untrusted user input. This vulnerability has been assigned the CVE identifier CVE-2023-28120.
Versions Affected: All. Not affected: None Fixed Versions: 7.0.4.3, 6.1.7.3
Impact
ActiveSupport uses the SafeBuffer string subclass to tag strings as html_safe after they have been sanitized. When these strings are mutated, the tag is should be removed to mark them as no longer being html_safe.
Ruby 3.2 introduced a new bytesplice method which ActiveSupport did not yet understand to be a mutation. Users on older versions of Ruby are likely unaffected.
All users running an affected release and using bytesplice should either upgrade or use one of the workarounds immediately.
Workarounds
Avoid calling bytesplice on a SafeBuffer (html_safe) string with untrusted user input.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | activesupport | ≥ 7.0.0&&< 7.0.4.3 | 7.0.4.3 |
| 💎RubyGems | activesupport | all versions | 6.1.7.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for activesupport. 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 activesupport to 7.0.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pj73-v5mw-pm9j 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-pj73-v5mw-pm9j 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-pj73-v5mw-pm9j. 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-pj73-v5mw-pm9j in your dependencies?
O3 detects GHSA-pj73-v5mw-pm9j across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.