How severe is CVE-2025-54476?

No CVSS score has been assigned to CVE-2025-54476 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-54476?

CVE-2025-54476 affects the following packages: joomla/filter (Packagist), joomla/filter (Packagist), joomla/filter (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2025-54476?

Update joomla/filter to 4.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-54476 is resolved across your whole dependency graph.

How do I detect CVE-2025-54476 in my Packagist dependencies?

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

How do I mitigate CVE-2025-54476 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 CVE-2025-54476 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-54476 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-2025-54476?

CVE-2025-54476 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 25th 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-2025-54476?

CVE-2025-54476 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 CVE-2025-54476 published, and has it been updated?

CVE-2025-54476 was published on September 30, 2025 and was last updated on October 1, 2025. 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

CVE-2025-54476 — filter

Fix: joomla-framework/filter@188dd3f

CVE-2025-54476 is a Cross-site Scripting (XSS) vulnerability in joomla/filter. A fix is available for joomla/filter — see the affected versions and patch details below.

Joomla! CMS vulnerable to XSS via the input filter

Published

Sep 30, 2025

Updated

Oct 1, 2025

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Nov 7, 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-2025-54476.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs25th percentile — riskier than 25% of all scored CVEsHighest risk

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

Real-World Exposure

3 pkgs affected

🐘joomla/filter🐘joomla/filter🐘joomla/filter

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

Improper handling of input could lead to a cross-site scripting (XSS) vector in the checkAttribute method of the input filter framework class.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`joomla/filter`	≥ 4.0.0&&< 4.0.1	4.0.1`composer require joomla/filter:^4.0.1`
🐘Packagist	`joomla/filter`	≥ 3.0.0&&< 3.0.5	3.0.5`composer require joomla/filter:^3.0.5`
🐘Packagist	`joomla/filter`	all versions	2.0.6`composer require joomla/filter:^2.0.6`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for joomla/filter, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update joomla/filter to 4.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-54476 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

Improper handling of input could lead to a cross-site scripting (XSS) vector in the checkAttribute method of the input filter framework class.

O3 Security · Impact-Aware SCA

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