WordPress Core < 6.0.3 — Shared User Instance Weakness
0fcdfba2-aa19-4d0c-8880-5ee2c0680555Published · Updated Action summary
Affected: ≤6.0.2Update to 3.7.40 or 3.8.40 or 3.9.38 or 4.0.37 or 4.1.37 or 4.2.34 or 4.3.30 or 4.4.29 or 4.5.28 or 4.6.25 or 4.7.25 or 4.8.21 or 4.9.22 or 5.0.18 or 5.1.15 or 5.2.17 or 5.3.14 or 5.4.12 or 5.5.11 or 5.6.10 or 5.7.8 or 5.8.6 or 5.9.5 or 6.0.3 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
- 0fcdfba2-aa19-4d0c-8880-5ee2c0680555
- Product
- WordPress wordpress
- Affected
- ≤6.0.2
- Fixed in
- 3.7.40, 3.8.40, 3.9.38, 4.0.37, 4.1.37, 4.2.34, 4.3.30, 4.4.29, 4.5.28, 4.6.25, 4.7.25, 4.8.21, 4.9.22, 5.0.18, 5.1.15, 5.2.17, 5.3.14, 5.4.12, 5.5.11, 5.6.10, 5.7.8, 5.8.6, 5.9.5, 6.0.3
- Required access
- No account needed
- Published
- · updated
- Credit
- Ben Bidner, Alex Concha
- Affected≤ 6.0.2
- Patched in3.7.40 / 3.8.40 / 3.9.38 / 4.0.37 / 4.1.37 / 4.2.34 / 4.3.30 / 4.4.29 / 4.5.28 / 4.6.25 / 4.7.25 / 4.8.21 / 4.9.22 / 5.0.18 / 5.1.15 / 5.2.17 / 5.3.14 / 5.4.12 / 5.5.11 / 5.6.10 / 5.7.8 / 5.8.6 / 5.9.5 / 6.0.3
Update to 3.7.40 / 3.8.40 / 3.9.38 / 4.0.37 / 4.1.37 / 4.2.34 / 4.3.30 / 4.4.29 / 4.5.28 / 4.6.25 / 4.7.25 / 4.8.21 / 4.9.22 / 5.0.18 / 5.1.15 / 5.2.17 / 5.3.14 / 5.4.12 / 5.5.11 / 5.6.10 / 5.7.8 / 5.8.6 / 5.9.5 / 6.0.3 or newer.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:HAttack complexity- High
PR:NPrivileges required- None
UI:NUser interaction- None
S:UScope- Unchanged
C:NConfidentiality- None
I:LIntegrity- Low
A:NAvailability- None
WordPress Core in versions up to 6.0.3 had a weakness in how Share User Instances were handled. This fix appears to have been necessary to safely use the wp_set_current_user( 0 ); method to patch the previously mentioned XSS and CSRF in wp-mail.php and wp-trackback.php vulnerabilities.
The previous functionality may have resulted in third party plugins or themes using the wp_set_current_user function in a way that could lead to privilege escalation and users being able to perform more actions than originally intended.
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: 3.7.40, 3.8.40, 3.9.38, 4.0.37, 4.1.37, 4.2.34, 4.3.30, 4.4.29, 4.5.28, 4.6.25, 4.7.25, 4.8.21, 4.9.22, 5.0.18, 5.1.15, 5.2.17, 5.3.14, 5.4.12, 5.5.11, 5.6.10, 5.7.8, 5.8.6, 5.9.5, 6.0.3
- 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 low, CVSS 3.7
Record last updated
Sources & licenses
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.