CVE-2026-18391: WooCommerce Subscriptions (WordPress plugin) · Code Injection
Affects WooCommerce Subscriptions (WordPress plugin)Source CVE Database V5
Not known to be exploited · CVSS 9.8 Critical : upgrade to 9.1.0 as a priority.
Data as of 9 Nov 2026, 23:24 UTC
- EPSS
- 0.9% chance of exploitation in 30 days – higher than 61% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 9.1.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade WooCommerce Subscriptions (WordPress plugin) to 9.1.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| WooCommerce Subscriptions | Affected
| Fixed in
|
Packagistwoocommerce/subscriptionspkg:composer/woocommerce/subscriptionsOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, users should consider disabling High-Performance Order Storage if feasible or restrict access to vulnerable endpoints to trusted users only.
Description
The WooCommerce Subscriptions WordPress plugin before 9.1.0 does not validate user input before unserializing it on stores with High-Performance Order Storage enabled, leading to a PHP Object Injection issue which unauthenticated users can escalate to Remote Code Execution via a gadget chain present in the bundled dependencies.