# CVE-2026-61456: Grav before 1.0.3 Stored XSS via SVG Upload API

> An authenticated attacker can upload malicious SVG files to execute JavaScript in an administrator's session, enabling cookie theft and session hijacking.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/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:** 10 Jul 2026
- **Updated:** 10 Jul 2026
- **Also known as:** GHSA-g78v-pr5g-35v2

## What is CVE-2026-61456?

CVE-2026-61456 is a medium-severity cross-site scripting vulnerability in getgrav grav, published on 10 Jul 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

The Grav API plugin (getgrav/grav-plugin-api) before 1.0.3 fails to sanitize SVG files uploaded through the POST /api/v1/media endpoint. The HandlesMediaUploads::processUploadedFile() method validates only the file extension and never invokes Security::sanitizeSVG(), so an authenticated attacker with the api.media.write permission can upload an SVG containing arbitrary JavaScript. The file is stored unmodified and served with Content-Type: image/svg+xml; when an administrator opens it in a browser (directly or via <object>/<iframe>), the embedded script executes in their session context, enabling cookie theft and session hijacking.

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

## Which versions are affected by CVE-2026-61456?


## How do I fix CVE-2026-61456?

No fix has been published for CVE-2026-61456 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-61456 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-61456 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-61456 and fix it if it is affected.

What it is: CVE-2026-61456 is a medium-severity cross-site scripting vulnerability in getgrav grav, published on 10 Jul 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-2026-61456 exists.

Affected product: getgrav grav. 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-2026-61456/ (Markdown: https://insights.sbomify.com/CVE-2026-61456/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-61456
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-61456
- OSV: https://osv.dev/vulnerability/CVE-2026-61456

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-61456/
Summaries are generated and may contain mistakes; the official description above is the record.