How severe is CVE-2021-27916?

CVE-2021-27916 has a CVSS score of 8.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-27916?

CVE-2021-27916 affects the following packages: mautic/core (Packagist), mautic/core (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-27916?

Update mautic/core to 4.4.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-27916 is resolved across your whole dependency graph.

How do I detect CVE-2021-27916 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mautic/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-27916 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2021-27916 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-27916 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-27916?

CVE-2021-27916 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 57th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-27916?

CVE-2021-27916 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-27916 published, and has it been updated?

CVE-2021-27916 was published on September 17, 2024 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

HIGH severity

CVE-2021-27916 — core

HIGHFix: mautic/mautic@546045f

CVE-2021-27916 is a high-severity (CVSS 8.1) Path Traversal vulnerability in mautic/core. A fix is available for mautic/core — see the affected versions and patch details below.

Mautic vulnerable to Relative Path Traversal / Arbitrary File Deletion due to GrapesJS builder

Also known asGHSA-9fcx-cv56-w58p

Published

Sep 17, 2024

Updated

Oct 20, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2021-27916.

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs57th percentile — riskier than 57% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

🐘mautic/core🐘mautic/core

Real-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

Prior to the patched version, logged in users of Mautic are vulnerable to Relative Path Traversal/Arbitrary File Deletion. Regardless of the level of access the Mautic user had, they could delete files other than those in the media folders such as system files, libraries or other important files.

This vulnerability exists in the implementation of the GrapesJS builder in Mautic.

Patches

Update to 4.4.12 or 5.0.4.

Workarounds

References

For more information

If you have any questions or comments about this advisory:

Email us at [email protected]

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`mautic/core`	≥ 3.3.0&&< 4.4.12	4.4.12`composer require mautic/core:^4.4.12`
🐘Packagist	`mautic/core`	≥ 5.0.0-alpha&&< 5.0.4	5.0.4`composer require mautic/core:^5.0.4`

Affected Products

1 product · 2 configurations

Application

mauticacquia

≥ 5.0.0 && < 5.0.4

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mautic/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mautic/core to 4.4.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-27916 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

### Impact Prior to the patched version, logged in users of Mautic are vulnerable to Relative Path Traversal/Arbitrary File Deletion. Regardless of the level of access the Mautic user had, they could delete files other than those in the media folders such as system files, libraries or other important files. This vulnerability exists in the implementation of the GrapesJS builder in Mautic. ### Patches Update to 4.4.12 or 5.0.4. ### Workarounds No ### References - https://cwe.mitre.org/data/definitions/23.html - https://cwe.mitre.org/data/definitions/22.html - https://attack.mitre.org/techn