Mastodon
CVE-2023-36461
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V2 - Validation and Business Logic Resource allocation limits
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | A remote attacker could exhaust system resources through uncontrolled allocation by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Mastodon is a free, open-source social network server based on ActivityPub. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Allocation of Resources Without Limits vulnerability could allow attackers to exhaust system resources through uncontrolled allocation.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Set resource limits, implement rate limiting, validate input sizes.
Affects your stack
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Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Allocation of Resources Without Limits (CWE-770), which allows attackers to exhaust system resources through uncontrolled allocation. Mastodon is a free, open-source social network server based on ActivityPub. When performing outgoing HTTP queries, Mastodon sets a timeout on individual read operations. Prior to versions 3.5.9, 4.0.5, and 4.1.3, a malicious server can indefinitely extend the duration of the response through slowloris-type attacks. This vulnerability can be used to keep all Mastodon workers busy for an extended duration of time, leading to the server becoming unresponsive. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue. Affected products include: Joinmastodon Mastodon.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Mastodon is a free, open-source social network server based on ActivityPub. When performing outgoing HTTP queries, Mastodon sets a timeout on individual read operations. Prior to versions 3.5.9, 4.0.5, and 4.1.3, a malicious server can indefinitely extend the duration of the response through slowloris-type attacks. This vulnerability can be used to keep all Mastodon workers busy for an extended duration of time, leading to the server becoming unresponsive. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)NVD
Mastodon through 4.0.2 allows attackers to cause a denial of service (large Sidekiq pull queue) by creating bot accounts
Mastodon is a free, open-source social network server based on ActivityPub. Rated high severity (CVSS 7.4), this vulnera
Mastodon is a free, open-source social network server based on ActivityPub Mastodon allows configuration of LDAP for aut
Mastodon is a free, open-source social network server based on ActivityPub. Rated critical severity (CVSS 9.9), this vul
Mastodon is a free, open-source social network server based on ActivityPub Mastodon allows configuration of LDAP for aut
Improper Restriction of Excessive Authentication Attempts in GitHub repository mastodon/mastodon prior to 4.0.0. Rated c
Server-Side Request Forgery in Mastodon before 4.5.10, 4.4.17, and 4.3.23 lets attackers coerce the server into issuing
Server-side request forgery in Mastodon (versions before 4.5.10, 4.4.17, and 4.3.23) lets an attacker who controls autho
Mastodon prior to versions 4.5.8, 4.4.15, and 4.3.21 contains an unauthenticated Open Redirect vulnerability in the `/we
Unauthenticated attackers can bypass FASP administrator approval in Mastodon 4.4.0-4.4.13 and 4.5.0-4.5.6 to subscribe t
Sign-up restriction bypass in Mastodon (self-hosted ActivityPub social server) before v4.5.9, v4.4.16, and v4.3.22 allow
Mastodon is a self-hosted, federated microblogging platform. Rated high severity (CVSS 8.2), this vulnerability is remot
Exploit-DB