# CVE-2023-26486: Vega `scale` expression function cross site scripting

> Attackers can execute arbitrary JavaScript by exploiting the Vega scale expression function to escape the sandbox, affecting applications using this visualization library.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Mar 2023
- **Updated:** 25 Feb 2025
- **Also known as:** DEBIAN-CVE-2023-26486, GHSA-4vq7-882g-wcg4

## What is CVE-2023-26486?

CVE-2023-26486 is a medium-severity cross-site scripting vulnerability in vega, published on 3 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Vega is a visualization grammar, a declarative format for creating, saving, and sharing interactive visualization designs. The Vega `scale` expression function has the ability to call arbitrary functions with a single controlled argument. The scale expression function passes a user supplied argument group to getScale, which is then used as if it were an internal context. The context.scales[name].value is accessed from group and called as a function back in scale. This can be exploited to escape the Vega expression sandbox in order to execute arbitrary JavaScript. This issue has been fixed in version 5.13.1.

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

## Which versions are affected by CVE-2023-26486?

4 open source packages ship an affected version, including vega and vega-functions. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `vega` | npm | All versions | 5.23.0 |
| `vega` | npm | All versions | 5.23.0 |
| `vega-functions` | npm | All versions | 5.13.1 |
| `vega-functions` | npm | All versions | 5.13.1 |

Products: Vega-Functions Project Vega-Functions, Vega Project Vega.

## How do I fix CVE-2023-26486?

Upgrade vega to 5.23.0 or later.

## Is CVE-2023-26486 being exploited?

There is no known exploitation of CVE-2023-26486 in the wild and no public exploit code.

## Other vulnerabilities in vega

- [CVE-2025-66648](https://insights.sbomify.com/CVE-2025-66648/): `vega-functions` vulnerable to Cross-site Scripting via `setdata` function (high 7.2)
- [CVE-2023-26487](https://insights.sbomify.com/CVE-2023-26487/): Vega has cross-site scripting vulnerability in `lassoAppend` function (medium 6.5)
- [CVE-2025-26619](https://insights.sbomify.com/CVE-2025-26619/): Vega Cross-Site Scripting (XSS) via event filter when not using CSP mode `expressionInterpeter` (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-26486 and fix it if it is affected.

What it is: CVE-2023-26486 is a medium-severity cross-site scripting vulnerability in vega, published on 3 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-26486 in the wild and no public exploit code.

Affected packages and fixed versions:
- vega (npm): affected all versions; fixed in 5.23.0
- vega (npm): affected all versions; fixed in 5.23.0
- vega-functions (npm): affected all versions; fixed in 5.13.1
- vega-functions (npm): affected all versions; fixed in 5.13.1

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-2023-26486/ (Markdown: https://insights.sbomify.com/CVE-2023-26486/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-26486
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-26486
- OSV: https://osv.dev/vulnerability/CVE-2023-26486

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-26486/
Summaries are generated and may contain mistakes; the official description above is the record.