CVE-2026-6275: StatCounter <= 2.1.1 - Authenticated (Author+) Stored Cross-Site Scripting via Author Nickname

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.3%

EPSS score, percentile 23.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

6.4 Medium

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• 2.1.1 and earlier

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: unaffected.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

The StatCounter – Free Real Time Visitor Stats plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.1.1 This is due to insufficient output escaping on the post author's nickname in the statcounter_addToTags() function. The function is hooked to wp_head and fires on every single post page. It retrieves the post author's nickname via the_author_meta(…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-6275 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 29 May 2026.
• The CVE record carries a CVSS v3.1 base score of 6.4 (Medium), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 23.2), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
• The credits in the CVE record name ZAST.AI as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

StatCounter <= 2.1.1 - Authenticated (Author+) Stored Cross-Site Scripting via Author Nickname

The StatCounter – Free Real Time Visitor Stats plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.1.1 This is due to insufficient output escaping on the post author's nickname in the statcounter_addToTags() function. The function is hooked to wp_head and fires on every single post page. It retrieves the post author's nickname via the_author_meta() and echoes it directly into a JavaScript double-quoted string context inside a <script> block without applying esc_js() or any equivalent JavaScript-context escaping. This makes it possible for authenticated attackers with Author-level access and above to inject arbitrary web scripts into pages that will execute whenever any user (including unauthenticated visitors) accesses a post authored by the attacker.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline