# CVE-2026-63156: Omnispace Agora Project < 26.10.0 Reflected XSS via visioUrl Parameter

> Unauthenticated attackers can execute arbitrary JavaScript in victims' browsers via a malicious visioUrl parameter in Omnispace Agora Project.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/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:** 13 Oct 2026
- **Updated:** 27 Oct 2026
- **Also known as:** GHSA-mwm7-gw2j-5q99

## What is CVE-2026-63156?

CVE-2026-63156 is a medium-severity cross-site scripting vulnerability in Omnispace Agora Project, published on 13 Oct 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

Omnispace Agora Project before 26.10.0 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious HTML attributes by manipulating the visioUrl parameter, which was not routed through the URL-sanitizing branch of the parameter filter and was urldecoded after filtering. Attackers can craft a malicious URL containing the visioUrl parameter with an attribute breakout payload to execute arbitrary JavaScript in the victim's browser pre-authentication, with the issue fixed in version 26.10.0 via changes to app/Common/Req.php.

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

## Which versions are affected by CVE-2026-63156?


## How do I fix CVE-2026-63156?

No fix has been published for CVE-2026-63156 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-63156 being exploited?

There is no known exploitation of CVE-2026-63156 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63156 and fix it if it is affected.

What it is: CVE-2026-63156 is a medium-severity cross-site scripting vulnerability in Omnispace Agora Project, published on 13 Oct 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: There is no known exploitation of CVE-2026-63156 in the wild and no public exploit code.

Affected product: Omnispace Agora Project. 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-2026-63156/ (Markdown: https://insights.sbomify.com/CVE-2026-63156/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63156
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63156
- OSV: https://osv.dev/vulnerability/CVE-2026-63156

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-63156/
Summaries are generated and may contain mistakes; the official description above is the record.