How severe is CVE-2019-12473?

CVE-2019-12473 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2019-12473?

CVE-2019-12473 affects the following packages: mediawiki/core (Packagist), mediawiki/core (Packagist), mediawiki/core (Packagist), mediawiki/core (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2019-12473?

Update mediawiki/core to 1.27.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-12473 is resolved across your whole dependency graph.

How do I detect CVE-2019-12473 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mediawiki/core. 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-2019-12473 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-2019-12473?

O3 pinpoints whether CVE-2019-12473 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-2019-12473 actively exploited in the wild?

No public exploit code has been indexed for CVE-2019-12473 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-2019-12473 published, and has it been updated?

CVE-2019-12473 was published on July 10, 2019 and was last updated on July 8, 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

CVE-2019-12473

HIGH

CVE-2019-12473 is a high-severity (CVSS 7.5) vulnerability in mediawiki/core. O3 Security confirms whether CVE-2019-12473 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Wikimedia Potential DOS due to slow WatchedItemStore::countVisitingWatchersMultiple

Also known asGHSA-33xw-x3pr-rvqj

Published

Jul 10, 2019

Updated

Jul 8, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Blast Radius

4 pkgs affected

🐘mediawiki/core🐘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 1.27.0 through 1.32.1 might allow DoS. Passing invalid titles to the API could cause a DoS by querying the entire watchlist table. Fixed in 1.32.2, 1.31.2, 1.30.2 and 1.27.6.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`mediawiki/core`	≥ 1.27.0&&< 1.27.6	1.27.6
🐘Packagist	`mediawiki/core`	≥ 1.30.0&&< 1.30.2	1.30.2
🐘Packagist	`mediawiki/core`	≥ 1.31.0&&< 1.31.2	1.31.2
🐘Packagist	`mediawiki/core`	≥ 1.32.0&&< 1.32.2	1.32.2

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. 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 mediawiki/core to 1.27.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-12473 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-2019-12473 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-2019-12473. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Wikimedia MediaWiki 1.27.0 through 1.32.1 might allow DoS. Passing invalid titles to the API could cause a DoS by querying the entire watchlist table. Fixed in 1.32.2, 1.31.2, 1.30.2 and 1.27.6.

O3 Security · Impact-Aware SCA

Is CVE-2019-12473 in your dependencies?

O3 detects CVE-2019-12473 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