How severe is CVE-2021-43836?

CVE-2021-43836 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-43836?

CVE-2021-43836 affects the following packages: sulu/sulu (Packagist), sulu/sulu (Packagist), sulu/sulu (Packagist), sulu/sulu (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-43836?

Update sulu/sulu to 1.6.44 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-43836 is resolved across your whole dependency graph.

How do I detect CVE-2021-43836 in my Packagist dependencies?

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

How do I mitigate CVE-2021-43836 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-2021-43836 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-43836 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-2021-43836?

CVE-2021-43836 has an EPSS (Exploit Prediction Scoring System) score of 2.0%, placing it in the 81th 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-2021-43836?

CVE-2021-43836 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-2021-43836 published, and has it been updated?

CVE-2021-43836 was published on December 15, 2021 and was last updated on August 7, 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-2021-43836 — sulu

HIGHFix: sulu/sulu@9c948f9

CVE-2021-43836 is a high-severity (CVSS 8.8) Path Traversal vulnerability in sulu/sulu. A fix is available for sulu/sulu — see the affected versions and patch details below.

PHP file inclusion in the Sulu admin panel

Also known asGHSA-vx6j-pjrh-vgjh

Published

Dec 15, 2021

Updated

Aug 7, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Oct 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.0%probability of exploitation in next 30 days

Lower Risk+0.07%

Lower risk than most CVEs81th percentile — riskier than 81% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-43836 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

4 pkgs affected

🐘sulu/sulu🐘sulu/sulu🐘sulu/sulu🐘sulu/sulu

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

What kind of vulnerability is it? Who is impacted?

An attacker can read arbitrary local files via a PHP file include. In a default configuration this also leads to remote code execution.

Compromised components: Arbitrary file read on the server, (Potential) Remote code execution
Exploitation pre-requisite: User account on the backend

Patches

Has the problem been patched? What versions should users upgrade to?

The problem is patched with the Versions 1.6.44, 2.2.18, 2.3.8, 2.4.0

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

Overwrite the service sulu_route.generator.expression_token_provider and wrap the translator before passing it to the expression language.

References

Are there any links users can visit to find out more?

Currently not.

For more information

If you have any questions or comments about this advisory:

Open an issue in example link to repo
Email us at example email address

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`sulu/sulu`	all versions	1.6.44`composer require sulu/sulu:^1.6.44`
🐘Packagist	`sulu/sulu`	≥ 2.0.0&&< 2.2.18	2.2.18`composer require sulu/sulu:^2.2.18`
🐘Packagist	`sulu/sulu`	≥ 2.3.0&&< 2.3.8	2.3.8`composer require sulu/sulu:^2.3.8`
🐘Packagist	`sulu/sulu`	≥ 2.4.0-RC1&&< 2.4.0	2.4.0`composer require sulu/sulu:^2.4.0`

Affected Products

1 product · 4 configurations

Application

sulusulu

≥ 2.3.0 && < 2.3.8

1 version

2.4.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sulu/sulu, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update sulu/sulu to 1.6.44 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-43836 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 _What kind of vulnerability is it? Who is impacted?_ An attacker can read arbitrary local files via a PHP file include. In a default configuration this also leads to remote code execution. * Compromised components: Arbitrary file read on the server, (Potential) Remote code execution * Exploitation pre-requisite: User account on the backend ### Patches _Has the problem been patched? What versions should users upgrade to?_ The problem is patched with the Versions 1.6.44, 2.2.18, 2.3.8, 2.4.0 ### Workarounds _Is there a way for users to fix or remediate the vulnerability without