# CVE-2026-91078: TillKit < 1.0.5 - Unauthenticated POS Takeover via Hard-Coded Default Manager PIN

> Unauthenticated attackers can use a hard-coded PIN to access the POS interface, allowing them to read customer data and modify store information.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/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:** 3 Oct 2026
- **Updated:** 3 Oct 2026
- **Also known as:** GHSA-mhjv-47jj-mxpp

## What is CVE-2026-91078?

CVE-2026-91078 is a high-severity vulnerability in Unknown TillKit, published on 3 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The TillKit WordPress plugin before 1.0.5 does not require the hard-coded, publicly known PIN of the privileged POS account it creates on activation to be changed before use, and it authenticates its public POS login endpoint on that PIN alone with no identity or capability check, allowing unauthenticated attackers to obtain a privileged POS session and thereby read customer and site-user personal data and modify store data.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-91078?


## How do I fix CVE-2026-91078?

No fix has been published for CVE-2026-91078 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-91078 being exploited?

There is no known exploitation of CVE-2026-91078 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-91078 and fix it if it is affected.

What it is: CVE-2026-91078 is a high-severity vulnerability in Unknown TillKit, published on 3 Oct 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-2026-91078 in the wild and no public exploit code.

Affected product: Unknown TillKit. 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-2026-91078/ (Markdown: https://insights.sbomify.com/CVE-2026-91078/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-91078
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-91078
- OSV: https://osv.dev/vulnerability/CVE-2026-91078

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-91078/
Summaries are generated and may contain mistakes; the official description above is the record.