# CVE-2026-30691: @cyntler/react-doc-viewer's TXTRenderer fails to sanitize file content and explicitly casts raw data as a ReactNode

> Remote attackers can execute arbitrary JavaScript via crafted text files due to unsanitized content in the React document viewer library.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 20 May 2026
- **Updated:** 20 May 2026
- **Also known as:** GHSA-fvhg-p4hf-79x3

## What is CVE-2026-30691?

CVE-2026-30691 is a medium-severity cross-site scripting vulnerability in n/a, published on 20 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Cross-Site Scripting (XSS) vulnerability in @cyntler/react-doc-viewer v1.17.1 allows remote attackers to execute arbitrary JavaScript via a crafted .txt file. The TXTRenderer component fails to sanitize file content and explicitly casts raw data as a ReactNode

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

## Which versions are affected by CVE-2026-30691?

2 open source packages ship an affected version, including @cyntler/react-doc-viewer.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@cyntler/react-doc-viewer` | npm | All versions to 1.17.1 | None |
| `@cyntler/react-doc-viewer` | npm | All versions to 1.17.1 | None |

## How do I fix CVE-2026-30691?

No fix has been published for CVE-2026-30691 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-30691 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-30691 exists.

Public exploit code:

- CVE-2026-30691: Stored Cross-Site Scripting (XSS) in @cyntler/react-doc-viewer (github_poc): https://github.com/walidriouah/CVE-2026-30691

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-30691 and fix it if it is affected.

What it is: CVE-2026-30691 is a medium-severity cross-site scripting vulnerability in n/a, published on 20 May 2026. An attacker can exploit it over the internet without logging in, 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-2026-30691 exists.

Affected packages and fixed versions:
- @cyntler/react-doc-viewer (npm): affected all versions up to 1.17.1; no fix listed
- @cyntler/react-doc-viewer (npm): affected all versions up to 1.17.1; no fix listed

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-2026-30691/ (Markdown: https://insights.sbomify.com/CVE-2026-30691/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-30691
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-30691
- OSV: https://osv.dev/vulnerability/CVE-2026-30691

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-30691/
Summaries are generated and may contain mistakes; the official description above is the record.