GHSA-gg6x-xx78-448c is a medium-severity (CVSS 4) CWE-87 vulnerability in october/backend. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-gg6x-xx78-448c is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Reflected XSS when importing CSV in OctoberCMS
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
GHSA-gg6x-xx78-448c 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 371,256 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
october/backendReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
A user with the ability to use the import functionality of the ImportExportController behavior could be socially engineered by an attacker to upload a maliciously crafted CSV file which could result in a reflected XSS attack on the user in question
Patches
Issue has been patched in Build 466 (v1.0.466).
Workarounds
Apply https://github.com/octobercms/october/commit/cd0b6a791f995d86071a024464c1702efc50f46c to your installation manually if unable to upgrade to Build 466.
References
Reported by Sivanesh Ashok
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Threat assessment:
<img width="1100" alt="Screen Shot 2020-03-31 at 2 01 52 PM" src="https://user-images.githubusercontent.com/7253840/78070158-8f7ef580-7358-11ea-950c-226533f6a0a3.png">Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | october/backend | ≥ 1.0.319&&< 1.0.466 | 1.0.466 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for october/backend. 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 october/backend to 1.0.466 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gg6x-xx78-448c 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-gg6x-xx78-448c 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-gg6x-xx78-448c. 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-gg6x-xx78-448c in your dependencies?
O3 detects GHSA-gg6x-xx78-448c across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.