# CVE-2024-49363

## Summary

- **CVE ID:** CVE-2024-49363
- **Severity:** HIGH
- **CVSS Score:** 7.4 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H)
- **CWE:** CWE-405, CWE-674
- **Published:** Dec 18, 2024
- **Last Modified:** Mar 13, 2026

## Description

Misskey is an open source, federated social media platform. In affected versions FileServerService (media proxy) in github.com/misskey-dev/misskey 2024.10.1 or earlier did not detect proxy loops, which allows remote actors to execute a self-propagating reflected/amplified distributed denial-of-service via a maliciously crafted note. FileServerService.prototype.proxyHandler did not check incoming requests are not coming from another proxy server. An attacker can execute an amplified denial-of-service by sending a nested proxy request to the server and end the request with a malicious redirect back to another nested proxy request.
Leading to unbounded recursion until the original request is timed out. This issue has been addressed in version 2024.11.0-alpha.3. Users are advised to upgrade. Users unable to upgrade may configure the reverse proxy to block requests to the proxy with an empty User-Agent header or one containing Misskey/. An attacker can not effectively modify the User-Agent header without making another request to the server.

## Affected Products

- misskey-dev — misskey (< CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H)

## References

- [CNA](https://github.com/misskey-dev/misskey/security/advisories/GHSA-gq5q-c77c-v236)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.31%
- **EPSS Percentile:** 23.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._