GHSA-2j26-frm8-cmj9
Rails Active Support has a possible DoS vulnerability in its number helpers
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💎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
Impact
Active Support number helpers accept strings containing scientific notation (e.g. 1e10000), which when converted to a string could be expanded into extremely large decimal representations. This can cause excessive memory allocation and CPU consumption when the expanded number is formatted, possibly resulting in a DoS vulnerability.
Releases
The fixed releases are available at the normal locations.
Credit
This issue was responsibly reported by Hackerone researcher manun.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | activesupport | ≥ 8.1.0.beta1&&< 8.1.2.1 | 8.1.2.1 |
| 💎RubyGems | activesupport | ≥ 8.0.0.beta1&&< 8.0.4.1 | 8.0.4.1 |
| 💎RubyGems | activesupport | all versions | 7.2.3.1 |
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 8.1.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-2j26-frm8-cmj9 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-2j26-frm8-cmj9 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-2j26-frm8-cmj9. 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-2j26-frm8-cmj9 in your dependencies?
O3 detects GHSA-2j26-frm8-cmj9 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.