# CVE-2026-104466: YesWiki before 4.6.7 Stored XSS via Wakka Markdown Image src Attribute

> Attackers can inject JavaScript via markdown image URLs in YesWiki, potentially executing code in administrators' browsers.

- **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:** 2 Oct 2026
- **Updated:** 2 Oct 2026
- **Also known as:** GHSA-7pv9-pwm8-cwwr, GHSA-jjg5-rgm8-pvxr

## What is CVE-2026-104466?

CVE-2026-104466 is a medium-severity cross-site scripting vulnerability in yeswiki, published on 2 Oct 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

YesWiki before 4.6.7 contains a stored cross-site scripting vulnerability in formatters/wakka.php that allows users who can edit pages or post comments to inject event handlers by placing quotes in markdown image URLs. Attackers can store a crafted markdown image whose src breaks out of the attribute to add an onerror handler, executing JavaScript in viewers' browsers, including administrators.

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

## Which versions are affected by CVE-2026-104466?


## How do I fix CVE-2026-104466?

No fix has been published for CVE-2026-104466 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104466 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-104466 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104466 and fix it if it is affected.

What it is: CVE-2026-104466 is a medium-severity cross-site scripting vulnerability in yeswiki, published on 2 Oct 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-2026-104466 exists.

Affected product: yeswiki. 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-2026-104466/ (Markdown: https://insights.sbomify.com/CVE-2026-104466/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104466
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104466
- OSV: https://osv.dev/vulnerability/CVE-2026-104466

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104466/
Summaries are generated and may contain mistakes; the official description above is the record.