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 restrict characters that a...
Vendor
joinmastodon vulnerabilities
42 published CVES affecting joinmastodon, from public sources (CVE.org, NVD, CISA KEV, FIRST EPSS, OSV).
- Total
- 42
- Critical
- 5
- High
- 12
- Medium
- 23
- Low
- 2
- Unscored
- 0
- CISA KEV
- 0
Products
Latest joinmastodon CVEs
Newest publication first · page 1 of 2
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HighCVSS 8.2 EPSS 0.21%
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MediumCVSS 4.8 EPSS 0.17%
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 correctly processed on th...
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MediumCVSS 6.1 EPSS 0.47%
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 segments. An attacker can craf...
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MediumCVSS 4.6 EPSS 0.31%
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 attacker-chosen base_url t...
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MediumCVSS 4.8 EPSS 0.30%
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 lifecycle events or to...
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MediumCVSS 6.5 EPSS 0.44%
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 and featured hashtags...
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MediumCVSS 5.4 EPSS 0.23%
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 subscription by guessin...
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CVE-2026-23963 Mastodon missing length limits on list names, filter names, and filter keywords
PublishedMediumCVSS 6.5 EPSS 0.35%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 arbitrarily long string as...
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CVE-2026-23962 Mastodon vulnerable to Denial of Service from a single post (client/server)
PublishedHighCVSS 7.5 EPSS 0.55%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 amount of options, gr...
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MediumCVSS 5.3 EPSS 0.44%
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 timelines if boosted. Fur...
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MediumCVSS 4.3 EPSS 0.27%
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 download lists of seve...
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HighCVSS 7.1 EPSS 0.29%
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 specified in ALLOWED_P...
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CVE-2025-67500 Mastodon Error Handling Discrepancy Enables Private Status Existence Enumeration
PublishedLowCVSS 3.7 EPSS 0.24%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 given status exists by se...
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MediumCVSS 4.3 EPSS 0.29%
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 4.4.8 and 4.5.0-beta.2....
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MediumCVSS 4.3 EPSS 0.27%
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 lack the read:statuses...
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MediumCVSS 4.3 EPSS 0.24%
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 to continue receivin...
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LowCVSS 3.5 EPSS 0.22%
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, active sessions and...
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HighCVSS 7.5 EPSS 0.61%
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 critical configuratio...
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MediumCVSS 5.3 EPSS 0.36%
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 view the block reason...
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MediumCVSS 5.3 EPSS 0.37%
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 an arbitrary addresses....
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HighCVSS 7.5 EPSS 0.47%
Mastodon 4.1.x before 4.1.17 and 4.2.x before 4.2.9 allows a bypass of rate limiting via a crafted HTTP request header.
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MediumCVSS 5.9 EPSS 0.38%
In Mastodon 4.1.6, API endpoint rate limiting can be bypassed by setting a crafted HTTP request header.
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CVE-2024-37903 Mastodon has improper authorship check on audience extension for existing posts
PublishedHighCVSS 8.2 EPSS 0.53%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 server, thus gaining...
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HighCVSS 7.7 EPSS 0.51%
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 of the Activity Streams...
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MediumCVSS 4.3 EPSS 0.36%
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 allowing an application...
Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.