# CVE-2026-86838: Bookly < 28.3 - Unauthenticated Payment Bypass via Booking Price Manipulation

> Unauthenticated attackers can manipulate booking quantities to bypass payment validation and book paid services for free.

- **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:** 28 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-8vmp-w5gv-wxrj

## What is CVE-2026-86838?

CVE-2026-86838 is a medium-severity vulnerability in Unknown Bookly, published on 28 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Bookly WordPress plugin before 28.3 does not validate client-supplied booking quantity values on the server before computing the appointment total, allowing unauthenticated users to reduce the total to zero and book paid services for free while bypassing the payment step.

Weakness: CWE-472 (External Control of Assumed-Immutable Web Parameter)

## Which versions are affected by CVE-2026-86838?


## How do I fix CVE-2026-86838?

No fix has been published for CVE-2026-86838 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86838 being exploited?

There is no known exploitation of CVE-2026-86838 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86838 and fix it if it is affected.

What it is: CVE-2026-86838 is a medium-severity vulnerability in Unknown Bookly, published on 28 Sep 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-2026-86838 in the wild and no public exploit code.

Affected product: Unknown Bookly. 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-2026-86838/ (Markdown: https://insights.sbomify.com/CVE-2026-86838/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86838
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86838
- OSV: https://osv.dev/vulnerability/CVE-2026-86838

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86838/
Summaries are generated and may contain mistakes; the official description above is the record.