Cachet vulnerable to new line injection during configuration edition

Exploitation

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

CVSS

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

EPSS

• CVE-2021-39172: 29.17% estimated exploitation activity in the next 30 days; percentile 98.17 (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 Authenticated users, regardless of their privileges (User or Admin), can exploit a new line injection in the configuration edition feature (e.g. mail settings) and gain arbitrary code execution on the server. Patches This issue was addressed by improving UpdateConfigCommandHandler and preventing the use of new lines characters in new configuration values. Workarounds Only allow trusted source IP addresses to access to the administration dashboard. References - https://blog.sonarsource.com/cachet-code-execution-via-laravel-configuration-injection For more information If you have any questions or comments about this advisory, you can contact: - The original reporters, by sending an email to vulnerability.research [at] sonarsource.com; - The maintainers, by opening an issue on this repository.

Published by the source

30 Aug 2021, 16:11 UTC

Last modified by the source

22 May 2023, 16:23 UTC

Source last checked

26 Oct 2026, 14:05 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-9jxw-cfrh-jxq6

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# Patch Next advisory brief: CVE-2021-39172

Advisory: Cachet vulnerable to new line injection during configuration edition
IDs: CVE-2021-39172, GHSA-9jxw-cfrh-jxq6
Record: https://patchnext.com/advisories/cve-2021-39172 (revision 1, source checked 26 Oct 2026, 14:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: cachethq/cachet 2.5.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist cachethq/cachet: affected < 2.5.1; fixed in 2.5.1

## Suggested inspection (read-only)
- Packagist cachethq/cachet: 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 cachethq/cachet.
- 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-9jxw-cfrh-jxq6 (GitHub-reviewed advisory GHSA-9jxw-cfrh-jxq6 lists affected ranges: Packagist cachethq/cachet >=0 <2.5.1)

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