Appointments <= 2.2.1 - Unauthenticated PHP Object Injection
Published Oct 18, 2025
9.8
CRITICALCVSS 3.1
EPSS 0.73%
Description
The Appointments plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2.2.1 via deserialization of untrusted input from the `wpmudev_appointments` cookie. This allows unauthenticated attackers to inject a PHP Object. Attackers were actively exploiting this vulnerability with the WP_Theme() class to create backdoors.
Affected products
-
- Version 0StatusaffectedConstraints<2.2.2
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Wpmudev | Appointments | unaffected |
|
- ≤ 2.2.1
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
TotalDecision
n/aAssessed Oct 20, 2025 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2025–2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.73% (0.00735) | 52.73th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.67% (0.00670) | 46.95th | v5 (v2026.06.15) |
| Oct 18, 2025 | 0.04% (0.00038) | 11.11th | v4 (v2025.03.14) |
References (3)
- https://plugins.trac.wordpress.org/changeset/1733186/appointments Patch
- https://www.wordfence.com/blog/2017/10/3-zero-day-plugin-vulnerabilities-exploited-wild/ Press/Media CoverageThird Party Advisory
- https://www.wordfence.com/threat-intel/vulnerabilities/id/7e8f230e-3f96-4efd-806d-72725b960303?source=cve Third Party Advisory
| Link | Providers | Tags |
|---|---|---|
| https://plugins.trac.wordpress.org/changeset/1733186/appointments | Patch | |
| https://www.wordfence.com/blog/2017/10/3-zero-day-plugin-vulnerabilities-exploited-wild/ | Press/Media CoverageThird Party Advisory | |
| https://www.wordfence.com/threat-intel/vulnerabilities/id/7e8f230e-3f96-4efd-806d-72725b960303?source=cve | Third Party Advisory |
Change history (0)
No recorded changes yet.