How severe is CVE-2019-12471?

CVE-2019-12471 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 CVE-2019-12471?

CVE-2019-12471 affects the following packages: mediawiki/core (Packagist), mediawiki/core (Packagist), mediawiki/core (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2019-12471?

Update mediawiki/core to 1.27.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-12471 is resolved across your whole dependency graph.

How do I detect CVE-2019-12471 in my Packagist dependencies?

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

How do I mitigate CVE-2019-12471 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-2019-12471 actively exploited in the wild?

No public exploit code has been indexed for CVE-2019-12471 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-2019-12471?

CVE-2019-12471 has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 70th 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-2019-12471?

CVE-2019-12471 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-2019-12471 published, and has it been updated?

CVE-2019-12471 was published on July 10, 2019 and was last updated on October 24, 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-2019-12471 — core

MEDIUM

CVE-2019-12471 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in mediawiki/core. A fix is available for mediawiki/core — see the affected versions and patch details below.

MediaWiki Cross-site Scripting (XSS)

Also known asGHSA-2rm7-xxx8-35jh

Published

Jul 10, 2019

Updated

Oct 24, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs70th percentile — riskier than 70% 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

3 pkgs affected

🐘mediawiki/core🐘mediawiki/core🐘mediawiki/core

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

Wikimedia MediaWiki 1.30.0 through 1.32.1 has XSS. Loading user JavaScript from a non-existent account allows anyone to create the account, and perform XSS on users loading that script. Fixed in 1.32.2, 1.31.2, 1.30.2 and 1.27.6.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`mediawiki/core`	≥ 1.27.0&&< 1.27.6	1.27.6`composer require mediawiki/core:^1.27.6`
🐘Packagist	`mediawiki/core`	≥ 1.30.0&&< 1.30.2	1.30.2`composer require mediawiki/core:^1.30.2`
🐘Packagist	`mediawiki/core`	≥ 1.31.0&&< 1.31.2	1.31.2`composer require mediawiki/core:^1.31.2`

Affected Products

2 products · 4 configurations

debian linuxdebian

1 version

9.0

Application

mediawikimediawiki

≥ 1.32.0 && < 1.32.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mediawiki/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mediawiki/core to 1.27.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-12471 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

O3 Security · Impact-Aware SCA

Is CVE-2019-12471 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

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:3.0/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 Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

security-advisories

4.8/10

Maintained10/10

Code-Review10/10

Branch-Protection0/10

Assessed Nov 2, 2026

Timeline

Disclosed

Jul 10, 2019

Last updated

Oct 24, 2026

Identifiers

CVE-2019-12471

GHSA-2rm7-xxx8-35jh

References

Advisoryphabricator.wikimedia.org · T207603 Advisoryseclists.org Advisorydebian.org · dsa 4460 Advisorynvd.nist.gov · CVE 2019 12471 Fixlists.wikimedia.org Webgithub.com · CVE 2019 12471.yaml Packagegithub.com · mediawiki

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting mediawiki/core are rated as high or higher (top: critical).

CVE-2023-45363CVE-2023-29141CVE-2019-12466CVE-2020-25815CVE-2019-12474CVE-2019-12473CVE-2020-25814CVE-2019-12467

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026