6.4

CVE-2026-103427: wordpress simple-membership Cross-site Scripting

CVSS: 6.4v3.1MediumDeferred
Published 10-10-2026Last modified 11-10-2026
Open JSON

Vulnerability summary

CVE-2026-103427 is a medium (CVSS 6.4) Cross-site Scripting vulnerability in wordpress simple-membership. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 10.6% of scored vulnerabilities. Fixed in 4.8.5.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.4/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.21%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 10-10-2026
    PublishedVulnerability first disclosed.
  2. 11-10-2026
    Last modifiedVulnerability information updated.

Description

The Simple Membership plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'country' parameter in all versions up to, and including, 4.8.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Unauthenticated attackers may also exploit this vulnerability when the plugin's Enable Free Membership feature is turned on, as it permits anonymous front-end registration and profile submission.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.21%

Chance of exploitation in the next 30 days

Percentile

11%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

10-10-202620-10-2026
EPSS score
0.21%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Wordpress1 product
  • simple-membership≤ 4.8.4 (fixed in 4.8.5)
Wpinsider-11 product

2 vendors · 2 products

References

6 links