How severe is GHSA-h58v-c6rf-g9f7?

GHSA-h58v-c6rf-g9f7 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-h58v-c6rf-g9f7?

GHSA-h58v-c6rf-g9f7 affects the following packages: contao/core-bundle (Packagist), contao/core-bundle (Packagist), contao/contao (Packagist), contao/contao (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-h58v-c6rf-g9f7?

Update contao/core-bundle to 4.9.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h58v-c6rf-g9f7 is resolved across your whole dependency graph.

How do I detect GHSA-h58v-c6rf-g9f7 in my Packagist dependencies?

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

How do I mitigate GHSA-h58v-c6rf-g9f7 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is GHSA-h58v-c6rf-g9f7 actively exploited in the wild?

No public exploit code has been indexed for GHSA-h58v-c6rf-g9f7 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 GHSA-h58v-c6rf-g9f7?

GHSA-h58v-c6rf-g9f7 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 53th 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 GHSA-h58v-c6rf-g9f7?

GHSA-h58v-c6rf-g9f7 is classified as Cross-site Scripting (XSS) (CWE-79). 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 GHSA-h58v-c6rf-g9f7 published, and has it been updated?

GHSA-h58v-c6rf-g9f7 was published on July 1, 2021 and was last updated on September 10, 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

Cross site scripting in the system logGHSA-h58v-c6rf-g9f7

MEDIUM

GHSA-h58v-c6rf-g9f7 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in contao/core-bundle. A fix is available for contao/core-bundle — see the affected versions and patch details below.

Also known asCVE-2021-35210

Published

Jul 1, 2021

Updated

Sep 10, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs53th percentile — riskier than 53% of all scored CVEsHighest risk

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

How urgent is this, really

GHSA-h58v-c6rf-g9f7 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 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

🐘contao/core-bundle🐘contao/core-bundle🐘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

Impact

It is possible to inject code into the tl_log table that will be executed in the browser when the system log is called in the back end.

Patches

Update to Contao 4.9.16 or 4.11.5.

Workarounds

Disable the system log module in the back end for all users (especially admin users).

References

https://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021

For more information

If you have any questions or comments about this advisory, open an issue in contao/contao.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`contao/core-bundle`	≥ 4.5.0&&< 4.9.16	4.9.16`composer require contao/core-bundle:^4.9.16`
🐘Packagist	`contao/core-bundle`	≥ 4.10.0&&< 4.11.5	4.11.5`composer require contao/core-bundle:^4.11.5`
🐘Packagist	`contao/contao`	≥ 4.5.0&&< 4.9.16	4.9.16`composer require contao/contao:^4.9.16`
🐘Packagist	`contao/contao`	≥ 4.10.0&&< 4.11.5	4.11.5`composer require contao/contao:^4.11.5`

Affected Products

1 product · 2 configurations

Application

contaocontao

≥ 4.10.0 && < 4.11.5

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for contao/core-bundle, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update contao/core-bundle to 4.9.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h58v-c6rf-g9f7 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Impact It is possible to inject code into the `tl_log` table that will be executed in the browser when the system log is called in the back end. ### Patches Update to Contao 4.9.16 or 4.11.5. ### Workarounds Disable the system log module in the back end for all users (especially admin users). ### References https://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021 ### For more information If you have any questions or comments about this advisory, open an issue in [contao/contao](https://github.com/contao/contao/issues/new/choose).

O3 Security · Impact-Aware SCA

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Find it across Packagist, including transitive dependencies.

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CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

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

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Jul 1, 2021

Last updated

Sep 10, 2026

Identifiers

GHSA-h58v-c6rf-g9f7

References

Advisorynvd.nist.gov Webgithub.com Webcontao.org Webgithub.com Webgithub.com Packagegithub.com

Related vulnerabilities

This CVE is medium severity; 5 of 8 other CVEs affecting contao/core-bundle are rated as high or higher (top: moderate).

CVE-2026-55824CVE-2026-55825CVE-2025-65961CVE-2025-65960CVE-2025-57756CVE-2025-57758CVE-2025-57759CVE-2025-57757

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedSep 10, 2026

Cross site scripting in the system logGHSA-h58v-c6rf-g9f7

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Impact

Patches

Workarounds

References

For more information

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is GHSA-h58v-c6rf-g9f7 in your dependencies?