How severe is GHSA-x6mh-rjwm-8ph7?

GHSA-x6mh-rjwm-8ph7 has a CVSS score of 6.8/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-x6mh-rjwm-8ph7?

GHSA-x6mh-rjwm-8ph7 affects the following packages: shuchkin/simplexlsx (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-x6mh-rjwm-8ph7?

Update shuchkin/simplexlsx to 1.1.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x6mh-rjwm-8ph7 is resolved across your whole dependency graph.

How do I detect GHSA-x6mh-rjwm-8ph7 in my Packagist dependencies?

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

How do I mitigate GHSA-x6mh-rjwm-8ph7 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-x6mh-rjwm-8ph7 actively exploited in the wild?

No public exploit code has been indexed for GHSA-x6mh-rjwm-8ph7 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-x6mh-rjwm-8ph7?

GHSA-x6mh-rjwm-8ph7 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 40th 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-x6mh-rjwm-8ph7?

GHSA-x6mh-rjwm-8ph7 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-x6mh-rjwm-8ph7 published, and has it been updated?

GHSA-x6mh-rjwm-8ph7 was published on December 12, 2024 and was last updated on December 12, 2024. 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 vulnerability in SimpleXLSXEx::readXfs and SimpeXLSX::toHTMLExGHSA-x6mh-rjwm-8ph7

MEDIUMFix: shuchkin/simplexlsx@cb4e716

GHSA-x6mh-rjwm-8ph7 is a medium-severity (CVSS 6.8) Cross-site Scripting (XSS) vulnerability in shuchkin/simplexlsx. A fix is available for shuchkin/simplexlsx — see the affected versions and patch details below.

Also known asCVE-2024-55878

Published

Dec 12, 2024

Updated

Dec 12, 2024

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 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 GHSA-x6mh-rjwm-8ph7.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs40th percentile — riskier than 40% 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

1 pkg affected

🐘shuchkin/simplexlsx

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

When calling the extended toHTMLEx method, it is possible to execute arbitrary JavaScript code.

Patches

The supplied patch resolves this vulnerability for SimpleXLSX. Use 1.1.12

Workarounds

Don't use direct publication via toHTMLEx

This vulnerability was discovered by Aleksey Solovev (Positive Technologies)

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`shuchkin/simplexlsx`	≥ 1.0.12&&< 1.1.12	1.1.12`composer require shuchkin/simplexlsx:^1.1.12`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for shuchkin/simplexlsx, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update shuchkin/simplexlsx to 1.1.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x6mh-rjwm-8ph7 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 When calling the extended toHTMLEx method, it is possible to execute arbitrary JavaScript code. ### Patches The supplied patch resolves this vulnerability for SimpleXLSX. Use 1.1.12 ### Workarounds Don't use direct publication via toHTMLEx *** This vulnerability was discovered by Aleksey Solovev (Positive Technologies)