Potential CSV Injection vector in OctoberCMS

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.0 · CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2020-5299: 1.00% estimated exploitation activity in the next 30 days; percentile 62.91 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Any users with the ability to modify any data that could eventually be exported as a CSV file from the ImportExportController could potentially introduce a CSV injection into the data to cause the generated CSV export file to be malicious. This requires attackers to achieve the following before a successful attack can be completed: 1. Have found a vulnerability in the victim's spreadsheet software of choice. 2. Control data that would potentially be exported through the ImportExportController by a theoretical victim. 3. Convince the victim to export above data as a CSV and run it in vulnerable spreadsheet software while also bypassing any sanity checks by said software. Patches Issue has been patched in Build 466 (v1.0.466). Workarounds Apply https://github.com/octobercms/library/commit/c84bf03f506052c848f2fddc05f24be631427a1a & https://github.com/octobercms/october/commit/802d8c8e09a2b342649393edb6d3ceb958851484 to your installation manually if unable to upgrade to Build 466.…

Published by the source

3 Jun 2020, 21:58 UTC

Last modified by the source

1 Feb 2023, 05:02 UTC

Source last checked

26 Oct 2026, 14:01 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4rhm-m2fp-hx7q

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# Patch Next advisory brief: CVE-2020-5299

Advisory: Potential CSV Injection vector in OctoberCMS
IDs: CVE-2020-5299, GHSA-4rhm-m2fp-hx7q
Record: https://patchnext.com/advisories/cve-2020-5299 (revision 1, source checked 26 Oct 2026, 14:01 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: october/backend 1.0.466. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist october/backend: affected >= 1.0.319, < 1.0.466; fixed in 1.0.466

## Suggested inspection (read-only)
- Packagist october/backend: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on october/backend.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-4rhm-m2fp-hx7q (GitHub-reviewed advisory GHSA-4rhm-m2fp-hx7q lists affected ranges: Packagist october/backend >=1.0.319 <1.0.466)

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