CVE-2021-41126
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedOctober is a Content Management System (CMS) and web platform built on the the Laravel PHP Framework. In affected versions administrator accounts which had previously been deleted may still be able to sign in to the backend using October CMS v2.0. The issue has been patched in v2.1.12 of the october/october package. There are no workarounds for this issue and all users should update.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThis is an authentication logic flaw in October CMS where administrator accounts that have been deleted from the system still retain the ability to authenticate to the backend. The user record is removed but the authentication mechanism fails to properly invalidate the deleted user's session/credentials, allowing continued access.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 2.0.0, < 2.1.12CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check October CMS installed versionLocate the version of the october/october package in your composer.lock file or check the backend System > Updates section for the installed version numberAffected if The installed version is greater than or equal to 2.0.0 and less than 2.1.12
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Identify deleted administrator accountsReview your backend user management for any administrator accounts that were deleted from the systemAffected if There are or were any administrator accounts that have been removed from the system since upgrading to a vulnerable version
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Check for active authentication tokensInspect the backend auth sessions or token storage mechanism for any active sessions that may still be valid for deleted user IDsAffected if Active authentication sessions exist for user IDs corresponding to deleted administrator accounts
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Review recent admin login activityCheck system logs or audit trails for successful backend logins by accounts that no longer exist in the user management interfaceAffected if Login events are recorded for administrator accounts that have been deleted from the system
Your environment is affected if you run October CMS version 2.0.0 through 2.1.11 and have deleted any administrator accounts who may still be able to authenticate to the backend.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2.1.12
Update October CMS to version 2.1.12 or later of the october/october package. No workarounds exist; all affected installations must be updated.
2.1.12
- Run `composer update october/october --no-interaction` to update the October CMS package
- Verify the update completed successfully by checking the installed version with `composer show october/october`
- Clear the application cache using `php artisan cache:clear`
- Clear compiled classes with `php artisan clear-compiled`
- Rebuild the application with `php artisan october:build` if needed
- Test backend administrator login to confirm the fix
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-41126 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-41126 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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