Async JavaScript <= 2.19.07.14 — Authenticated (Subscriber+) Stored Cross-Site Scripting
CVE-2020-36854Published · Updated Action summary
Affected: <2.20.02.27Update to 2.20.02.27 or newer
All remediation steps- Severity
- Medium6.4
- CVSS
- 6.4CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:LPrivileges required- Low
UI:NUser interaction- None
S:CScope- Changed
C:LConfidentiality- Low
I:LIntegrity- Low
A:NAvailability- None
- Weakness
- CWE-79 Cross-Site Scripting
- Required access
- Unknown
- Exploit prediction (EPSS)
- No score
- CISA KEV
- Not listed
On this page8
Am I affected?
Async JavaScript async-javascript
- Affected< 2.20.02.27
- Patched in2.20.02.27
Update to 2.20.02.27 or newer.
You are affected if you run < 2.20.02.27. Version 2.20.02.27 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Async JavaScript.
- No admin access? Run a passive check of your site. It reads public files only.
What to do
- Update to version 2.20.02.27, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch Async JavaScript to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Mikey Veenstra.
The Async JavaScript plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.19.07.14. This is due to missing authorization checks on the aj_steps AJAX aciton along with a lack on sanitization on the settings saved via the function. This makes it possible for authenticated attackers with subscriber level permissions and above to inject malicious web scripts into a page that execute whenever a user accesses that page.
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 Async JavaScript
All 2| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| Medium5.5 | Authenticated (Admin+) Cross-Site Scripting ≤2.20.12.09Update to 2.21.06.29 | — |
- Medium5.5Authenticated (Admin+) Cross-Site Scripting
≤2.20.12.09Update to 2.21.06.29
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
EZ SQL Reports Shortcode Widget and DB Backup
≤5.25.25Update to 5.26.45
- Critical9.8Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission
Chatterbug Forms – Fast, Flexible WordPress Form Builder
≤1.0.2Update to 1.1
- Critical9.8Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter
ELEX WordPress HelpDesk & Customer Ticketing System
≤3.3.9Update to 3.4.0
- Medium5.3Unauthenticated Sensitive Information Exposure in 'search' Parameter
Customer Reviews for WooCommerce
≤5.127.0Update to 5.128.0
Timeline
CVE published
Severity medium, CVSS 6.4
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- 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.
