# CVE-2026-50190: Shaarli vulnerable to stored XSS via raw bookmark title in document <title> element on public permalink page

> Attackers can execute arbitrary scripts in Shaarli via stored XSS in bookmark titles, potentially leading to administrator account takeover.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA: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 Aug 2026
- **Updated:** 20 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-50190, GHSA-xm98-h5jj-64xv, UBUNTU-CVE-2026-50190

## What is CVE-2026-50190?

CVE-2026-50190 is a high-severity cross-site scripting vulnerability in Shaarli, published on 20 Aug 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

Shaarli is a personal bookmarking service. Versions prior to 0.16.3 are vulnerable to stored XSS in `application/front/controller/visitor/BookmarkListController.php`. The `permalink` handler concatenates the raw `$bookmark->getTitle()` into the `pagetitle` template variable and the RainTPL template emits it into the document `<title>` element without HTML escaping. A bookmark title containing `</title><script>...</script>` closes the document title early and the injected script executes in the Shaarli origin for any visitor of `/shaare/{hash}`. Shaarli's metadata fetcher copies a remote page's `<title>` text verbatim into the local bookmark title, so an attacker who hosts an attacker-controlled URL and convinces an administrator to bookmark it plants the payload with no further interaction — and the resulting permalink fires for every visitor including the administrator on first save, providing a one-shot administrator account takeover. Version 0.16.3 fixes the issue.

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

## Which versions are affected by CVE-2026-50190?


## How do I fix CVE-2026-50190?

No fix has been published for CVE-2026-50190 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-50190 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50190 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-50190 and fix it if it is affected.

What it is: CVE-2026-50190 is a high-severity cross-site scripting vulnerability in Shaarli, published on 20 Aug 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-2026-50190 exists.

Affected product: Shaarli. 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-2026-50190/ (Markdown: https://insights.sbomify.com/CVE-2026-50190/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-50190
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-50190
- OSV: https://osv.dev/vulnerability/CVE-2026-50190

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-50190/
Summaries are generated and may contain mistakes; the official description above is the record.