# CVE-2021-47843: Tagstoo 2.0.1 - Stored XSS to RCE

> Attackers can inject malicious scripts via files or tags to execute arbitrary code on the victim's computer.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 15 Jan 2026
- **Updated:** 5 Mar 2026
- **Also known as:** GHSA-m46h-g9fm-378f

## What is CVE-2021-47843?

CVE-2021-47843 is a medium-severity cross-site scripting vulnerability in Tagstoo, published on 15 Jan 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Tagstoo 2.0.1 contains a stored cross-site scripting vulnerability that allows attackers to inject malicious payloads through files or custom tags. Attackers can execute arbitrary JavaScript code to spawn system processes, access files, and perform remote code execution on the victim's computer.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-47843?

It affects 1 product.


Products: Pabloandumundu Tagstoo.

## How do I fix CVE-2021-47843?

No fix has been published for CVE-2021-47843 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47843 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47843 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47843 and fix it if it is affected.

What it is: CVE-2021-47843 is a medium-severity cross-site scripting vulnerability in Tagstoo, published on 15 Jan 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47843 exists.

Affected product: Tagstoo. 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-2021-47843/ (Markdown: https://insights.sbomify.com/CVE-2021-47843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47843
- OSV: https://osv.dev/vulnerability/CVE-2021-47843

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-47843/
Summaries are generated and may contain mistakes; the official description above is the record.