GHSA-m8xx-3x29-84h8
backpack/crud is vulnerable to Cross-Site Scripting (XSS)
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
backpack/crud🐘backpack/crud🐘backpack/crudReal-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
It’s a “moderate” vulnerability… but being an admin panel, take this seriously. It’s difficult… but an attacker could conduct a targeted phishing campaign, in order to trick your users or admins to click a malicious link, which under very specific circumstances could give them information... or even admin access. It’s unlikely, but that’s not good enough in admin panels - It should be made impossible. That’s why you are bothered with this.
Patches
If you don’t have custom error views, the views provided by Backpack would output the exception message without escaping it, which made an attack possible using Reflected XSS, in some very specific circumstances (that we will not disclose). To fix those error views in Backpack 4.x and 5.x, please run:
composer update backpack/crud
php artisan backpack:fix
The problem has been patched in:
- v4.0.63
- v4.1.69
- v5.0.13
IMPORTANT! Running a
composer updateshould get you the patched version, but you also need to runphp artisan backpack:fixafterwards, to patch your published error views, if necessary.
Workarounds
Alternatively (if you don’t want to run composer update), you can manually look inside your error views in “resources/views/errors” and output e($exception->getMessage()) instead of $exception->getMessage(). That’s all there is to the fix, really.
What the maintainers have done about this
Acted as soon as our team found it (last week of March 2022):
- Pushed patches to 5.x, 4.1 and 4.0;
- Made it easy to apply the fix to existing projects, using a new
php artisan backpack:fixcommand; - Kept the specific circumstances a secret; as far as they know, only the maintainer's team knows about the niche case where this exploit is possible;
- Emailed all our licensed users, to have a chance to fix their projects before it’s public;
- Sent an email blast to our 25.000+ strong Security Newsletter;
- Made this public with a blog post and soon a CVE, after our community has had a reasonable chance to fix their projects;
- Will continue to monitor this and remind paying users to apply this fix if they haven’t;
For more information
If you have any questions or comments about this advisory:
- Open an issue in backpack/crud
- Email us at [email protected]
PS. You can read this blog post for more information.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | backpack/crud | ≥ 5.0.0&&< 5.0.13 | 5.0.13 |
| 🐘Packagist | backpack/crud | ≥ 4.1.0&&< 4.1.69 | 4.1.69 |
| 🐘Packagist | backpack/crud | all versions | 4.0.63 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for backpack/crud. 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 backpack/crud to 5.0.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m8xx-3x29-84h8 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-m8xx-3x29-84h8 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-m8xx-3x29-84h8. 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-m8xx-3x29-84h8 in your dependencies?
O3 detects GHSA-m8xx-3x29-84h8 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.