GHSA-496g-mmpw-j9x3

Suggest an improvement
Source
https://github.com/advisories/GHSA-496g-mmpw-j9x3
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/12/GHSA-496g-mmpw-j9x3/GHSA-496g-mmpw-j9x3.json
JSON Data
https://api.test.osv.dev/v1/vulns/GHSA-496g-mmpw-j9x3
Aliases
Published
2025-12-15T20:55:27Z
Modified
2025-12-15T21:11:26.124708Z
Severity
  • 7.1 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
misskey.js's export data contains private post data
Details

Summary

After adding private posts (followers, direct) that you do not have permission to view to your favorites or clips, you can export them to view the contents of the private posts.

PoC

  1. Create an account (X) for testing and an account (Y) for private posts on the same server.
  2. Send appropriate content from Y using "Follow"
  3. Send appropriate content to any user using "Nominate" from Y
  4. Obtain the URLs for the two posts above using Y's account.
  5. Query the URLs for the two posts using X and add them to your favorites or clips.
  6. Export your favorites or clips using X.
  7. Check the exported data.

Note: Verified in v2025.11.1

Impact

This could allow an attacker to view the contents of private posts. If you have pinned private posts, this could be a real problem, as the ID of the private post can be obtained by viewing the user page on the original server.

Database specific
{
    "nvd_published_at": null,
    "github_reviewed_at": "2025-12-15T20:55:27Z",
    "severity": "HIGH",
    "cwe_ids": [
        "CWE-862"
    ],
    "github_reviewed": true
}
References

Affected packages

npm / misskey-js

Package

Affected ranges

Type
SEMVER
Events
Introduced
13.0.0-beta.16
Fixed
2025.12.0