# CVE-2026-67617: Microweber CMS 2.0.20 Stored XSS via tag_names Parameter

> Admin-authenticated attackers can inject malicious JavaScript via the tag_names parameter, leading to script execution for visitors and potential session hijacking.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-793c-7c93-m769

## What is CVE-2026-67617?

CVE-2026-67617 is a medium-severity cross-site scripting vulnerability in microweber, published on 3 Aug 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Microweber CMS through 2.0.20 contains a stored cross-site scripting vulnerability in the content tagging system that allows admin-authenticated attackers to inject arbitrary JavaScript by submitting malicious payloads via the tag_names parameter of the GET /api/save_content_admin endpoint, bypassing three independent sanitization controls including XSS middleware that ignores GET requests, a strip_unsafe() function that only matches double-quoted onerror attributes, and a titlecase normalizer that passes HTML decimal entity-encoded payloads through unchanged. Attackers can store malicious scripts that execute without user interaction for every visitor to the public blog page and within the admin post editor, enabling session riding through same-origin fetch requests using the CSRF token embedded in the page.

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

## Which versions are affected by CVE-2026-67617?


## How do I fix CVE-2026-67617?

No fix has been published for CVE-2026-67617 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-67617 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67617 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-67617 and fix it if it is affected.

What it is: CVE-2026-67617 is a medium-severity cross-site scripting vulnerability in microweber, published on 3 Aug 2026. An attacker needs administrator access to exploit it, 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-2026-67617 exists.

Affected product: microweber. 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-2026-67617/ (Markdown: https://insights.sbomify.com/CVE-2026-67617/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-67617
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-67617
- OSV: https://osv.dev/vulnerability/CVE-2026-67617

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-67617/
Summaries are generated and may contain mistakes; the official description above is the record.