How severe is CVE-2018-20028?

CVE-2018-20028 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2018-20028?

CVE-2018-20028 affects the following packages: contao/contao (Packagist), contao/contao (Packagist), contao/contao (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2018-20028?

Update contao/contao to 3.5.37 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-20028 is resolved across your whole dependency graph.

How do I detect CVE-2018-20028 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for contao/contao. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2018-20028 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2018-20028?

O3 pinpoints whether CVE-2018-20028 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2018-20028 actively exploited in the wild?

No public exploit code has been indexed for CVE-2018-20028 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.

When was CVE-2018-20028 published, and has it been updated?

CVE-2018-20028 was published on April 17, 2019 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

MEDIUM severity

CVE-2018-20028

MEDIUM

CVE-2018-20028 is a medium-severity (CVSS 6.5) vulnerability in contao/contao. O3 Security confirms whether CVE-2018-20028 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Contao Information Disclosure via Access Control Flaws

Also known asGHSA-q99w-j4mj-7hj8

Published

Apr 17, 2019

Updated

Aug 7, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Aug 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

3 pkgs affected

🐘contao/contao🐘contao/contao🐘contao/contao

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

Contao 3.x before 3.5.37, 4.4.x before 4.4.31 and 4.6.x before 4.6.11 has Incorrect Access Control.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`contao/contao`	≥ 3.0.0&&< 3.5.37	3.5.37
🐘Packagist	`contao/contao`	≥ 4.6.0&&< 4.6.11	4.6.11
🐘Packagist	`contao/contao`	≥ 4.4.0&&< 4.4.31	4.4.31

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for contao/contao. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update contao/contao to 3.5.37 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-20028 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2018-20028 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2018-20028. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Contao 3.x before 3.5.37, 4.4.x before 4.4.31 and 4.6.x before 4.6.11 has Incorrect Access Control.

O3 Security · Impact-Aware SCA

Is CVE-2018-20028 in your dependencies?

O3 detects CVE-2018-20028 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works