GHSA-55mm-5399-7r63 is a medium-severity (CVSS 6.1) CWE-565 vulnerability in october/rain. A fix is available for october/rain — see the affected versions and patch details below.
Reliance on Cookies without validation 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-55mm-5399-7r63 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 377,166 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/rainReal-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
Previously encrypted cookie values were not tied to the name of the cookie the value belonged to. This meant that certain classes of attacks that took advantage of other theoretical vulnerabilities in user facing code (nothing exploitable in the core project itself) had a higher chance of succeeding.
Specifically, if your usage exposed a way for users to provide unfiltered user input and have it returned to them as an encrypted cookie (ex. storing a user provided search query in a cookie) they could then use the generated cookie in place of other more tightly controlled cookies; or if your usage exposed the plaintext version of an encrypted cookie at any point to the user they could theoretically provide encrypted content from your application back to it as an encrypted cookie and force the framework to decrypt it for them.
Patches
Issue has been patched in Build 468 (v1.0.468).
NOTE: If you are using the cookie session driver, all of your session data will be invalidated. All other session drivers should smoothly upgrade to the changes (although the backend authentication persist cookie will also be invalidated requiring users to login again once their current session expires).
Workarounds
Apply https://github.com/octobercms/library/commit/28310d4fb336a1741b39498f4474497644a6875c to your installation manually if unable to upgrade to Build 468.
References
- https://blog.laravel.com/laravel-cookie-security-releases
- https://github.com/laravel/framework/compare/4c7d118181d6c7f1f883643702df807ced016c5e...a731824421f9ebc586728ea9c7cff231a249aaa9
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Threat Assessment
Assessed as Low given that it is not directly exploitable within the core but requires other security vulnerabilities within the application to have an effect and the severity of its effect depends entirely on the severity of those other holes in the application's defences.
Acknowledgements
Thanks to Takashi Terada of Mitsui Bussan Secure Directions, Inc. for finding the original issue in Laravel and @taylorotwell for sharing the report with the October CMS team.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | october/rain | ≥ 1.0.319&&< 1.0.468 | 1.0.468composer require october/rain:^1.0.468 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for october/rain, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update october/rain to 1.0.468 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-55mm-5399-7r63 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-55mm-5399-7r63 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-55mm-5399-7r63. 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-55mm-5399-7r63 in your dependencies?
O3 Security finds GHSA-55mm-5399-7r63 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.