CVE-2025-62605Network attack vector

Unauthorized quote previews via reblog self-quotation

Published Oct 21, 2025 · Updated Oct 21, 2025

Improper quote validation in Mastodon allows remote authenticated users to display unauthorized post previews through quote posts. Quote validation accepts a reblog as the quoted status, letting an attacker quote that self-authored reblog while its preview exposes the original post without the author’s authorization. A low-privileged account able to reblog and quote a post is sufficient; the result bypasses quote controls but grants no reported broader data access.

CVSS severity4.3
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper quote validation in Mastodon allows remote authenticated users to display unauthorized post previews through quote posts. Quote validation accepts a reblog as the quoted status, letting an attacker quote that self-authored reblog while its preview exposes the original post without the author’s authorization. A low-privileged account able to reblog and quote a post is sufficient; the result bypasses quote controls but grants no reported broader data access.

The record

CVE
CVE-2025-62605
Published
Oct 21, 2025
Updated
Oct 21, 2025
Vendor
Mastodon
Product
Mastodon
Classifications
CWE-754
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 4.4.0-beta.1, < 4.4.8
  2. Affected versionversion== 4.5.0-beta.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mastodon · Mastodonversion=>= 4.4.0-beta.1, < 4.4.8; version== 4.5.0-beta.1

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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