CVE-2026-111862 (CVSS 9.8)

Description

Rank Math SEO PRO for WordPress is affected by a supply-chain compromise in a subset of version 3.0.123 packages downloaded or updated between October 15, 2026 at 20:02 UTC and October 16, 2026 at 07:12 UTC. Rank Math states that the affected plugin files contained malware that could compromise a website if the plugin was activated and directs sites that activated an affected package to treat the website as compromised. The malware may establish persistent access, communicate with rank1cdn[.]com, recreate hidden backdoors on page visits, and expose WordPress credentials, database credentials, API keys, and other secrets accessible to the web server. Rank Math identifies three malicious wp_options keys, hidden PHP backdoors, unauthorized administrator accounts, a fake WordPress core file, PHP-executable .cache files, and a system cron marker as incident indicators. Only packages obtained during the vendor-confirmed window are claimed as affected; version 3.0.123 alone is not sufficient to establish compromise. Rank Math removed the affected files and released version 3.0.124 as the clean replacement.

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CVSS v3.1 Score

9.8

CRITICAL

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

EPSS — Exploit Prediction

0.0066

Probability of exploitation

0.51%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-506 CWE-506

References

Other References

https://rankmath.com/changelog/ https://rankmath.com/kb/pro-3-0-123-security-incident/ https://rdap.verisign.com/com/v1/domain/rank1cdn.com https://urlscan.io/result/01a145c2-8dc8-72ff-a65d-21209ca29c4f/ https://www.wordfence.com/threat-intel/vulnerabilities/id/81cd7a2c-ad0c-4dbc-b5dc-07ec866d5c1f?source=cve

Frequently Asked Questions

What is CVE-2026-111862? +

Rank Math SEO PRO for WordPress is affected by a supply-chain compromise in a subset of version 3.0.123 packages downloaded or updated between October 15, 2026 at 20:02 UTC and October 16, 2026 at 07:12 UTC. Rank Math states that the affected plugin files contained malware that could compromise a website if the plugin was activated and directs sites that activated an affected package to treat the website as compromised. The malware may establish persistent access, communicate with rank1cdn[.]com, recreate hidden backdoors on page visits, and expose WordPress credentials, database credentials, API keys, and other secrets accessible to the web server. Rank Math identifies three malicious wp_options keys, hidden PHP backdoors, unauthorized administrator accounts, a fake WordPress core file, PHP-executable .cache files, and a system cron marker as incident indicators. Only packages obtained during the vendor-confirmed window are claimed as affected; version 3.0.123 alone is not sufficient to establish compromise. Rank Math removed the affected files and released version 3.0.124 as the clean replacement. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-111862? +

CVE-2026-111862 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0066, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-111862? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-111862