Possible cross-site scripting attack via unsanitized SVG files in FoF Upload

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.7 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

EPSS

• CVE-2022-30999: 1.26% estimated exploitation activity in the next 30 days; percentile 69.72 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact If FoF Upload is configured to allow the uploading of SVG files (image/svg+xml), navigating directly to an SVG file URI could execute arbitrary Javascript code decided by an attacker. This Javascript code could include the execution of HTTP web requests to Flarum, or any other web service. This could allow data to be leaked by an authenticated Flarum user, or, possibly, for data to be modified maliciously. Patches This has been patched with v1.2.3, which now sanitizes uploaded SVG files. Workarounds Upgrade to 1.2.3 (requires Flarum 1.2 or later), or remove the ability for users to upload SVG files through FoF Upload. References Thank you to Safwat Refaat for the responsible disclosure of this vulnerability.

Published by the source

25 May 2022, 22:55 UTC

Last modified by the source

27 Jan 2023, 05:07 UTC

Source last checked

26 Oct 2026, 14:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fm53-mpmp-7qw2

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# Patch Next advisory brief: CVE-2022-30999

Advisory: Possible cross-site scripting attack via unsanitized SVG files in FoF Upload
IDs: CVE-2022-30999, GHSA-fm53-mpmp-7qw2
Record: https://patchnext.com/advisories/cve-2022-30999 (revision 1, source checked 26 Oct 2026, 14:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: fof/upload 1.2.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist fof/upload: affected < 1.2.3; fixed in 1.2.3

## Suggested inspection (read-only)
- Packagist fof/upload: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on fof/upload.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-fm53-mpmp-7qw2 (GitHub-reviewed advisory GHSA-fm53-mpmp-7qw2 lists affected ranges: Packagist fof/upload >=0 <1.2.3)

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