---
id: CVE-2026-104817
title: 'Misskey is an open source, federated social media platform'
summary: >-
  Misskey is an open source, federated social media platform. From 12.112.1
  until 2026.7.0, the unauthenticated fetch-rss API lacks rate limiting and
  response-size restrictions and performs synchronous XML parsing. An attacker
  can trigger …
severity: high
cvss: 8.7
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:L/SI:N/SA:L'
cwe:
  - CWE-405
  - CWE-770
  - CWE-918
vendor: misskey-dev
product: misskey
affected:
  - 'misskey >= 12.0.0, <= 13.14.2'
  - 'misskey >= 2023.9.0-beta.1, < 2026.7.0'
published: '2026-10-13'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T20:04:29.760'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-104817'
references:
  - url: >-
      https://github.com/misskey-dev/misskey/commit/a12ee2e5d72c40252e11a164b2231667c9697667
    label: security-advisories@github.com
  - url: 'https://github.com/misskey-dev/misskey/releases/tag/2026.7.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/misskey-dev/misskey/security/advisories/GHSA-4x7v-qx8f-g3p8
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
epss: 0.0046
epssPercentile: 0.39649
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-13T19:03:52.462592Z'
cvssSource: cna
ingestedAt: '2026-10-13T19:43:28.909Z'
---

## Overview

Misskey is an open source, federated social media platform. From 12.112.1 until 2026.7.0, the unauthenticated fetch-rss API lacks rate limiting and response-size restrictions and performs synchronous XML parsing. An attacker can trigger unbounded outbound HTTP requests and synchronous parsing, exhausting instance resources, amplifying requests toward third-party servers, or probing network-reachable services even when federation is disabled. This issue is fixed in version 2026.7.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.