# CVE-2026-2888: Formidable Forms <= 6.28 - Unauthenticated Payment Amount Manipulation via 'item_meta' Parameter

> Unauthenticated attackers can manipulate payment amounts in Formidable Forms by exploiting dynamic pricing logic, allowing them to pay reduced prices for goods or services.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Mar 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-xc8q-rh3x-h9m3

## What is CVE-2026-2888?

CVE-2026-2888 is a medium-severity vulnerability in strategy11team Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Formidable Forms plugin for WordPress is vulnerable to an authorization bypass through user-controlled key in all versions up to, and including, 6.28. This is due to the `frm_strp_amount` AJAX handler (`update_intent_ajax`) overwriting the global `$_POST` data with attacker-controlled JSON input and then using those values to recalculate payment amounts via field shortcode resolution in `generate_false_entry()`. The handler relies on a nonce that is publicly exposed in the page's JavaScript (`frm_stripe_vars.nonce`), which provides CSRF protection but not authorization. This makes it possible for unauthenticated attackers to manipulate PaymentIntent amounts before payment completion on forms using dynamic pricing with field shortcodes, effectively paying a reduced amount for goods or services.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-2888?


## How do I fix CVE-2026-2888?

No fix has been published for CVE-2026-2888 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-2888 being exploited?

There is no known exploitation of CVE-2026-2888 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-2888 and fix it if it is affected.

What it is: CVE-2026-2888 is a medium-severity vulnerability in strategy11team Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-2888 in the wild and no public exploit code.

Affected product: strategy11team Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-2888/ (Markdown: https://insights.sbomify.com/CVE-2026-2888/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2888
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2888
- OSV: https://osv.dev/vulnerability/CVE-2026-2888

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-2888/
Summaries are generated and may contain mistakes; the official description above is the record.