WordPress Core < 5.9.1 — jQuery Prototype Pollution
CVE-2021-20083Published · Updated Action summary
Affected: ≤5.9.1Update to 3.7.38 or 3.8.38 or 3.9.36 or 4.0.35 or 4.1.35 or 4.2.32 or 4.3.28 or 4.4.27 or 4.5.26 or 4.6.23 or 4.7.23 or 4.8.19 or 4.9.20 or 5.0.16 or 5.1.13 or 5.2.15 or 5.3.12 or 5.4.10 or 5.5.9 or 5.6.8 or 5.7.6 or 5.8.4 or 5.9.2 or newer
Fixed versions are per release branch: update to the fix for the branch you run.
All remediation stepsOn this page3
Overview
- Advisory ID
- CVE-2021-20083
- Product
- WordPress wordpress
- Affected
- ≤5.9.1
- Fixed in
- 3.7.38, 3.8.38, 3.9.36, 4.0.35, 4.1.35, 4.2.32, 4.3.28, 4.4.27, 4.5.26, 4.6.23, 4.7.23, 4.8.19, 4.9.20, 5.0.16, 5.1.13, 5.2.15, 5.3.12, 5.4.10, 5.5.9, 5.6.8, 5.7.6, 5.8.4, 5.9.2
- Required access
- Unknown
- Published
- · updated
- Credit
- Melar Dev
- Source
- Wordfence Intelligence
- Affected≤ 5.9.1
- Patched in3.7.38 / 3.8.38 / 3.9.36 / 4.0.35 / 4.1.35 / 4.2.32 / 4.3.28 / 4.4.27 / 4.5.26 / 4.6.23 / 4.7.23 / 4.8.19 / 4.9.20 / 5.0.16 / 5.1.13 / 5.2.15 / 5.3.12 / 5.4.10 / 5.5.9 / 5.6.8 / 5.7.6 / 5.8.4 / 5.9.2
Update to 3.7.38 / 3.8.38 / 3.9.36 / 4.0.35 / 4.1.35 / 4.2.32 / 4.3.28 / 4.4.27 / 4.5.26 / 4.6.23 / 4.7.23 / 4.8.19 / 4.9.20 / 5.0.16 / 5.1.13 / 5.2.15 / 5.3.12 / 5.4.10 / 5.5.9 / 5.6.8 / 5.7.6 / 5.8.4 / 5.9.2 or newer.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:LPrivileges required- Low
UI:NUser interaction- None
S:UScope- Unchanged
C:HConfidentiality- High
I:HIntegrity- High
A:HAvailability- High
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in jquery-plugin-query-object 2.2.3 allows a malicious user to inject properties into Object.prototype.
Not sure which version you run? Run a passive check — it reads public files only.
Remediation & mitigations
- Update to one of the following versions, or a newer patched version: 3.7.38, 3.8.38, 3.9.36, 4.0.35, 4.1.35, 4.2.32, 4.3.28, 4.4.27, 4.5.26, 4.6.23, 4.7.23, 4.8.19, 4.9.20, 5.0.16, 5.1.13, 5.2.15, 5.3.12, 5.4.10, 5.5.9, 5.6.8, 5.7.6, 5.8.4, 5.9.2
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
References & provenance
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Timeline
CVE published
Severity high, CVSS 8.8
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.