# CVE-2026-103539: ZongXR SuperMarket Instant Buy InstantBuyController.java startBuy missing authentication

> Remote attackers can bypass authentication in the Instant Buy feature to perform unauthorized purchases or modify account data.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-72qv-6w2p-rq24

## What is CVE-2026-103539?

CVE-2026-103539 is a medium-severity missing authorization vulnerability in ZongXR SuperMarket, published on 1 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A weakness has been identified in ZongXR SuperMarket 1.0.0.0. This affects the function startBuy of the file instant-buy/src/main/java/com/supermarket/instantbuy/controller/InstantBuyController.java of the component Instant Buy. Executing a manipulation of the argument Username can lead to missing authentication. The attack may be performed from remote. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-306 (Missing Authentication for Critical Functionality), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-103539?


## How do I fix CVE-2026-103539?

No fix has been published for CVE-2026-103539 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103539 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103539 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103539 and fix it if it is affected.

What it is: CVE-2026-103539 is a medium-severity missing authorization vulnerability in ZongXR SuperMarket, published on 1 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103539 exists.

Affected product: ZongXR SuperMarket. 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-2026-103539/ (Markdown: https://insights.sbomify.com/CVE-2026-103539/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103539
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103539
- OSV: https://osv.dev/vulnerability/CVE-2026-103539

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103539/
Summaries are generated and may contain mistakes; the official description above is the record.