Answer in brief
CVE-2026-88764 records a Medium severity (CVSS 5.4) vulnerability in Simple Membership < 4.7.8 - Subscriber+ Membership Level Escalation via PayPal Standard subsc_ref. The current sources do not mark it as known exploited. The current feed maps Unknown/Simple Membership (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Unknown/Simple Membership (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Unknown/Simple Membershipgeneric | >=0 <4.7.8 | 4.7.8 |
Published upstream
Sep 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 13, 2026
The Simple Membership WordPress plugin before 4.7.8 does not validate that the membership level supplied in a PayPal payment notification matches the level configured for the paid payment button, allowing members to pay for a lower-priced membership while being granted a higher, more privileged membership level.
Quoted source text, attributed separately from HOL analysis.