# CVE-2026-86841: Bookly 23.2 - 28.2 - Bookly Administrator+ PHP Object Injection via Diagnostics Advanced Options

> Privileged users can inject PHP objects to execute code and read secrets in the Bookly WordPress plugin.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-ggx5-r53p-pf97

## What is CVE-2026-86841?

CVE-2026-86841 is a medium-severity unsafe deserialization vulnerability in Unknown Online Scheduling and Appointment Booking System, published on 27 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The Online Scheduling and Appointment Booking System  WordPress plugin before 28.3 does not prevent deserialization of untrusted input and does not correctly restrict a privileged maintenance feature to administrators, allowing users granted a custom booking-management capability, which an administrator must explicitly assign, to inject arbitrary PHP objects, overwrite privileged site options, and read stored integration secrets.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-86841?


## How do I fix CVE-2026-86841?

No fix has been published for CVE-2026-86841 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86841 being exploited?

There is no known exploitation of CVE-2026-86841 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86841 and fix it if it is affected.

What it is: CVE-2026-86841 is a medium-severity unsafe deserialization vulnerability in Unknown Online Scheduling and Appointment Booking System, published on 27 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-86841 in the wild and no public exploit code.

Affected product: Unknown Online Scheduling and Appointment Booking System. 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-2026-86841/ (Markdown: https://insights.sbomify.com/CVE-2026-86841/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86841
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86841
- OSV: https://osv.dev/vulnerability/CVE-2026-86841

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86841/
Summaries are generated and may contain mistakes; the official description above is the record.