Vendor
mastodon
46 known vulnerabilities.
mastodon at a glance
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| Month | Vulnerabilities | Critical |
|---|---|---|
| Nov 2026 | 0 | 0 |
| Oct 2026 | 0 | 0 |
| Sep 2026 | 0 | 0 |
| Aug 2026 | 4 | 0 |
| Jul 2026 | 0 | 0 |
| Jun 2026 | 7 | 0 |
| May 2026 | 0 | 0 |
| Apr 2026 | 1 | 0 |
| Mar 2026 | 2 | 0 |
| Feb 2026 | 3 | 0 |
| Jan 2026 | 6 | 0 |
| Dec 2025 | 1 | 0 |
| Nov 2025 | 0 | 0 |
| Oct 2025 | 4 | 0 |
| Sep 2025 | 0 | 0 |
| Aug 2025 | 1 | 0 |
| Jul 2025 | 0 | 0 |
| Jun 2025 | 0 | 0 |
| May 2025 | 0 | 0 |
| Apr 2025 | 0 | 0 |
| Mar 2025 | 0 | 0 |
| Feb 2025 | 2 | 0 |
| Jan 2025 | 0 | 0 |
| Dec 2024 | 0 | 0 |
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46 results · Feed
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High 7.4
Mastodon: Unwanted deactivation of SSL/TLS certificate verification
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.19 and from 4.5.0 until 4.5.12, Mastodon's app/models/concerns/user/ldap_authenticable.rb mutates OpenSSL::SSL::SSLContext::DEFAULT_PARAMS when LDAP authentication uses L…
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Medium 6.3
Mastodon: SSRF Protection Bypass via IPv4-compatible IPv6 Addresses
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.21, 4.5.14, 4.6.4, and 4.7.0-beta.1, PrivateAddressCheck.private_address? in app/lib/private_address_check.rb normalized IPv4-mapped IPv6 addresses but did not recognize …
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High 7.5
Mastodon: Personally-identifying information disclosure due to incorrect access control validation
Mastodon is a free, open-source social network server based on ActivityPub. From 4.6.0-beta.1 until 4.6.4 and 4.7.0-beta.1, any logged-in local user could use the show action in app/controllers/admin/collections_controller.rb to access personally identifying …
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High 7.5
Mastodon: Exhausting data by an unauthenticated request to the admin retention API
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.21, 4.5.14, 4.6.4, and 4.7.0-beta.1, the administrative statistics endpoints handled by Api::V1::Admin::MeasuresController and Api::V1::Admin::RetentionController checked…
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High 7.5
Mastodon: Persistent anonymous DoS via unhandled NoMethodError in MATH_TRANSFORMER
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.11, 4.4.18, and 4.3.24, a DoS can be triggered by (Uncaught Exception vulerability), due to missing exception handling in the math sanitizer. Malformed <math> nodes can r…
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Medium 5.3
Mastodon: Spoofing of attribution domains
Mastodon is a free, open-source social network server based on ActivityPub. From 4.3.0 until 4.5.11 and 4.4.18, Mastodon has a feature to let websites credit authors of their articles. To prevent false attribution claims, Mastodon uses the attributionDomains …
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Medium 6.5
Mastodon: Removal of integrity-protected JSON entries from signed activities
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon's normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain cla…
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High 8.6
Mastodon: SSRF protection bypass on older Ruby versions
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, when using Ruby versions older than 3.4, PrivateAddressCheck.private_address? returns false for IPv4-mapped IPv6 addresses (::ffff:a.b.c.d) corres…
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Medium 5.3
Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon's normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain cla…
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High 8.7
Mastodon: SSRF Bypass via IPv6 Unspecified Address (::)
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, the list of disallowed IP address ranges was lacking an IP address range that can be used to reach local IP addresses. An attacker can use an IP a…
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High 7.5CVE-2026-47777 Public exploit
Mastodon has a consent-check bypass in its remote Collections
Mastodon is a free, open-source social network server based on ActivityPub. In versions there is a missing condition in the check if remote accounts consented to be featured in a remote Collection could lead to attackers bypassing the check and faking consent…
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High 8.2
Mastodon: Insufficient verification of email addresses
Mastodon is a free, open-source social network server based on ActivityPub. Prior to v4.5.9, v4.4.16, and v4.3.22, Mastodon allows restricting new user sign-up based on e-mail domain names, and performs basic validation on e-mail addresses, but fails to restr…
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Medium 4.8
Mastodon has a denial of service for quote authorization
Mastodon is a free, open-source social network server based on ActivityPub. In versions on the 4.5.x branch prior to 4.5.8 and on the 4.4.x branch prior to 4.4.15, an attacker that knows of a quote before it has reached a server can prevent it from being corr…
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Medium 4.3
Mastodon has a GET-Based Open Redirect via '/web/%2F<domain>'
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.5.8, 4.4.15, and 4.3.21, an unauthenticated Open Redirect vulnerability (CWE-601) exists in the `/web/*` route due to improper handling of URL-encoded path segment…
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Medium 4.6
Mastodon has SSRF via unvalidated FASP Provider base_url
Mastodon is a free, open-source social network server based on ActivityPub. FASP registration requires manual approval by an administrator. In versions 4.4.0 through 4.4.13 and 4.5.0 through 4.5.6, an unauthenticated attacker can register a FASP with an attac…
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Medium 4.8
Mastodon may allow unconfirmed FASP to make subscriptions
Mastodon is a free, open-source social network server based on ActivityPub. FASP registration requires manual approval by an administrator. In versions 4.4.0 through 4.4.13 and 4.5.0 through 4.5.6, actions performed by a FASP to subscribe to account/content l…
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Medium 6.5
Mastodon's signature-dependent ActivityPub collection responses cached under signature-independent keys (Web Cache Poisoning via `Rails.cache`)
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.3.19, 4.4.13, 4.5.6, Mastodon is vulnerable to web cache poisoning via `Rails.cache. When AUTHORIZED_FETCH is enabled, the ActivityPub endpoints for pinned posts a…
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Medium 6.5
Mastodon has insufficient access control to push notification settings
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.5.5, 4.4.12, and 4.3.18, an insecure direct object reference in the web push subscription update endpoint lets any authenticated user update another user's push su…
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Medium 4.3
Mastodon missing length limits on list names, filter names, and filter keywords
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.5.5, 4.4.12, and 4.3.18, the server does not enforce a maximum length for the names of lists or filters, or for filter keywords, allowing any user to set an arbitr…
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High 7.5
Mastodon vulnerable to Denial of Service from a single post (client/server)
Mastodon is a free, open-source social network server based on ActivityPub. Mastodon versions before v4.3.18, v4.4.12, and v4.5.5 do not have a limit on the maximum number of poll options for remote posts, allowing attackers to create polls with a very large …
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Medium 5.3
Mastodon may allow a remote suspension bypass
Mastodon is a free, open-source social network server based on ActivityPub. Mastodon allows server administrators to suspend remote users to prevent interactions. However, some logic errors allow already-known posts from such suspended users to appear in time…
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Medium 6.5
Local Mastodon users can enumerate and access severed relationships of every other local user
Mastodon is a free, open-source social network server based on ActivityPub. Mastodon 4.3 added notifications of severed relationships, allowing end-users to inspect the relationships they lost as the result of a moderation action. The code allowing users to d…
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High 7.1
Mastodon has SSRF Protection bypass
Mastodon is a free, open-source social network server based on ActivityPub. By nature, Mastodon performs a lot of outbound requests to user-provided domains. Mastodon, however, has some protection mechanism to disallow requests to local IP addresses (unless s…
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Low 3.7
Mastodon Error Handling Discrepancy Enables Private Status Existence Enumeration
Mastodon is a free, open-source social network server based on ActivityPub. Versions 4.2.27 and prior, 4.3.0-beta.1 through 4.3.14, 4.4.0-beta.1 through 4.4.9, 4.5.0-beta.1 through 4.5.2 have discrepancies in error handling which allow checking whether a give…
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Medium 4.3
Mastodon quotes control can be bypassed
Mastodon is a free, open-source social network server based on ActivityPub. In Mastodon version 4.4, support for verifiable quote posts with quote controls was added, but it is possible for an attacker to bypass these controls in Mastodon versions prior to 4.…
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Medium 4.3
Mastadon streaming server allows OAuth clients without the `read` scope to subscribe to public channels
Mastodon is a free, open-source social network server based on ActivityPub. In Mastodon before 4.4.6, 4.3.14, and 4.2.27, the streaming server accepts serving events for public timelines to clients using any valid authentication token, even if those tokens la…
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Medium 4.3
Mastodon streaming API fails to disconnect disabled and suspended users
Mastodon is a free, open-source social network server based on ActivityPub. In versions before 4.4.6, 4.3.14, and 4.2.27, disabling or suspending a user account does not disconnect the account from the streaming API. This allows disabled or suspended accounts…
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Low 3.5
Mastodon allows continued access after password reset via CLI
Mastodon is a free, open-source social network server based on ActivityPub. In Mastodon before 4.4.6, 4.3.14, and 4.2.27, when an administrator resets a user account's password via the command-line interface using `bin/tootctl accounts modify --reset-password…
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Medium 5.3
Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails
Mastodon is a free, open-source social network server based on ActivityPub Mastodon which facilitates LDAP configuration for authentication. In versions 3.1.5 through 4.2.24, 4.3.0 through 4.3.11 and 4.4.0 through 4.4.3, Mastodon's rate-limiting system has a …
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Medium 5.3
Mastodon's domain blocks & rationales ignore user approval when visibility set as "users"
Mastodon is a self-hosted, federated microblogging platform. In versions prior to 4.1.23, 4.2.16, and 4.3.4, when the visibility for domain blocks/reasons is set to "users" (localized English string: "To logged-in users"), users that are not yet approved can …
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Medium 5.3
Mastodon's rate-limits are missing on `/auth/setup`
Mastodon is a self-hosted, federated microblogging platform. Starting in version 4.2.0 and prior to versions 4.2.16 and 4.3.4, the rate limits are missing on `/auth/setup`. Without those rate limits, an attacker can craft requests that will send an email to a…
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High 8.2
Mastodon has improper authorship check on audience extension for existing posts
Mastodon is a self-hosted, federated microblogging platform. Starting in version 2.6.0 and prior to versions 4.1.18 and 4.2.10, by crafting specific activities, an attacker can extend the audience of a post they do not own to other Mastodon users on a target …
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High 8.5
Lack of media type verification of Activity Streams objects allows impersonation of remote accounts
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19, when fetching remote statuses, Mastodon doesn't check that the response from the remote server has a `Content-Type` header value o…
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Low 3.1
Destroying OAuth Applications doesn't notify Streaming of Access Tokens being destroyed in mastodon
Mastodon is a free, open-source social network server based on ActivityPub. When an OAuth Application is destroyed, the streaming server wasn't being informed that the Access Tokens had also been destroyed, this could have posed security risks to users by all…
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Medium 4.2
External OpenID Connect Account Takeover by E-Mail Change in mastodon
Mastodon is a free, open-source social network server based on ActivityPub. Mastodon allows new identities from configured authentication providers (CAS, SAML, OIDC) to attach to existing local users with the same e-mail address. This results in a possible ac…
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Critical 9.4
Mastodon Remote user impersonation and takeover
Mastodon is a free, open-source social network server based on ActivityPub Mastodon allows configuration of LDAP for authentication. Due to insufficient origin validation in all Mastodon, attackers can impersonate and take over any remote account. Every Masto…
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Medium 6.1
Mastodon vulnerable to Stored XSS through the translation feature
Mastodon is a free, open-source social network server based on ActivityPub. In versions on the 4.x branch prior to versions 4.0.10, 4.2.8, and 4.2.0-rc2, under certain conditions, attackers can abuse the translation feature to bypass the server-side HTML sani…
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High 7.4
Mastodon Invalid Domain Name Normalization vulnerability
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 3.5.14, 4.0.10, 4.1.8, and 4.2.0-rc2, under certain circumstances, attackers can exploit a flaw in domain name normalization to spoof domains they do not own. Versio…
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Medium 5.4
Mastodon Server-Side Request Forgery vulnerability
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used…
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Medium 5.4
Mastodon's verified profile links can be formatted in a misleading way
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 2.6.0 and prior to versions 3.5.9, 4.0.5, and 4.1.3, an attacker can craft a verified profile link using specific formatting to conceal arbitrary parts of the link…