6.4

CVE-2026-77820: stellarwp wpcomplete Cross-site Scripting

CVSS: 6.4v3.1MediumDeferred
Published 19-09-2026Last modified 19-09-2026
Open JSON

Vulnerability summary

CVE-2026-77820 is a medium (CVSS 6.4) Cross-site Scripting vulnerability in stellarwp wpcomplete. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 24.8% of scored vulnerabilities. Fixed in 2.9.9.1.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.4/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.33%
0%100%
Low · +0.09 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 19-09-2026
    PublishedVulnerability first disclosed.
  2. 19-09-2026
    Last modifiedVulnerability information updated.

Description

The WPComplete plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'empty' Shortcode Attribute in all versions up to, and including, 2.9.9.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the premium version of the software in order to exploit. Please note this only affects the pro version.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.33%

Chance of exploitation in the next 30 days

Percentile

25%

Versus all other CVEs

30-day change

+0.09 pp

From 0.24% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.33%

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

Stellarwp1 product
Wordpress1 product
  • wpcomplete≤ 2.9.9.0 (fixed in 2.9.9.1)

2 vendors · 2 products

References

6 links