LMS by LifterLMS <= 4.21.0 — Reflected Cross-Site Scripting
daedec14-6177-43c7-89d4-a39c13d94ca4Published · Updated Action summary
Affected: <4.21.1Update to 4.21.1 or newer
All remediation steps- Severity
- Medium6.1
- CVSS
- 6.1CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:RUser interaction- Required
S:CScope- Changed
C:LConfidentiality- Low
I:LIntegrity- Low
A:NAvailability- None
- Weakness
- CWE-79 Cross-Site Scripting
- Required access
- No account needed
- Exploit prediction (EPSS)
- No score
- CISA KEV
- Not listed
On this page8
Am I affected?
LifterLMS – WP LMS for eLearning, Online Courses, & Quizzes lifterlms
- Affected< 4.21.1
- Patched in4.21.1
Update to 4.21.1 or newer.
You are affected if you run < 4.21.1. Version 4.21.1 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under LifterLMS – WP LMS for eLearning, Online Courses, & Quizzes.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 4.21.1, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch LifterLMS – WP LMS for eLearning, Online Courses, & Quizzes to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Ashish Jha.
The LMS by LifterLMS plugin for WordPress has a reflected cross-site scripting vulnerability in the in versions up to, and including, 4.21.0 due to insufficient input sanitization and output escaping on the 'coupon_code' parameter. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in LifterLMS – WP LMS for eLearning, Online Courses, & Quizzes
All 21| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| Medium6.4 | Authenticated (Subscriber+) Stored Cross-Site Scripting via Content Question Answer ≤10.3.2Update to 11.0.0 | CVE-2026-119098 | |
| High7.5 | Authenticated (Contributor+) Local File Inclusion via 'lifterlms_checkout' Shortcode Attributes ≤10.3.1Update to 10.3.2 | CVE-2026-110284 | |
| High8.8 | Authenticated (Custom+) PHP Object Injection via 'custom' Lesson Data ≤10.2.1Update to 10.3.0 | CVE-2026-104723 | |
| Medium6.4 | Authenticated (Custom role+) Stored Cross-Site Scripting ≤10.0.9Update to 10.0.10 | CVE-2026-14207 | |
| Medium4.3 | Authenticated (Subscriber+) Information Exposure <10.0.10Update to 10.0.10 | CVE-2026-14231 |
- Medium6.4Authenticated (Subscriber+) Stored Cross-Site Scripting via Content Question Answer
≤10.3.2Update to 11.0.0
- High7.5Authenticated (Contributor+) Local File Inclusion via 'lifterlms_checkout' Shortcode Attributes
≤10.3.1Update to 10.3.2
- High8.8Authenticated (Custom+) PHP Object Injection via 'custom' Lesson Data
≤10.2.1Update to 10.3.0
- Medium6.4Authenticated (Custom role+) Stored Cross-Site Scripting
≤10.0.9Update to 10.0.10
- Medium4.3Authenticated (Subscriber+) Information Exposure
<10.0.10Update to 10.0.10
Same weakness (Cross-Site Scripting)
All Cross-Site Scripting| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High7.2 | Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header | CVE-2026-120688 | |
| Critical9.8 | Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission | CVE-2026-125055 | |
| Critical9.8 | Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter | CVE-2026-119077 | |
| Medium5.3 | Unauthenticated Sensitive Information Exposure in 'search' Parameter | CVE-2026-121518 |
- High7.2Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header
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Timeline
CVE published
Severity medium, CVSS 6.1
Record last updated
Sources & licenses
- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.