Claire

31 exploits Active since Jul 2023
CVE-2024-37903 WRITEUP HIGH WRITEUP
Mastodon 2.6.0-4.1.18 - Unauthorized Post Audience Extension via Crafted Activities
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 access to the contents of a post not intended for them. Versions 4.1.18 and 4.2.10 contain a patch for this issue.
CVSS 8.2
CVE-2025-27399 WRITEUP MEDIUM WRITEUP
Mastodon <4.1.23-4.3.4 - Info Disclosure
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 reasons. Instance admins that do not want their domain blocks to be public are impacted. Versions 4.1.23, 4.2.16, and 4.3.4 fix the issue.
CVSS 5.3
CVE-2025-62605 WRITEUP MEDIUM WRITEUP
Mastodon 4.4.0-4.4.7 - Quote Control Bypass via Reblog
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. Mastodon internally treats reblogs as statuses. Since they were not special-treated, an attacker could reblog any post, then quote their reblog, technically quoting themselves, but having the quote feature a preview of the post they did not get authorization for with all of the affordances that would be otherwise denied by the quote controls. This issue has been patched in versions 4.4.8 and 4.5.0-beta.2.
CVSS 4.3
CVE-2026-22245 WRITEUP HIGH WRITEUP
Mastodon < 4.2.29 - Server-Side Request Forgery via IP Address Range 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 specified in `ALLOWED_PRIVATE_ADDRESSES`) to avoid the "confused deputy" problem. The list of disallowed IP address ranges was lacking some IP address ranges that can be used to reach local IP addresses. An attacker can use an IP address in the affected ranges to make Mastodon perform HTTP requests against loopback or local network hosts, potentially allowing access to otherwise private resources and services. This is fixed in Mastodon v4.5.4, v4.4.11, v4.3.17 and v4.2.29.
CVSS 7.5
CVE-2026-22246 WRITEUP MEDIUM WRITEUP
Mastodon < 4.3.17 - Unauthenticated Information Disclosure via Severed Relationship Notifications
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 severed relationships for a particular event fails to check the owner of the list before returning the lost relationships. Any registered local user can access the list of lost followers and followed users caused by any severance event, and go through all severance events this way. The leaked information does not include the name of the account which has lost follows and followers. This has been fixed in Mastodon v4.3.17, v4.4.11 and v4.5.4.
CVSS 6.5
CVE-2026-22245 WRITEUP HIGH WRITEUP
Mastodon < 4.2.29 - Server-Side Request Forgery via IP Address Range 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 specified in `ALLOWED_PRIVATE_ADDRESSES`) to avoid the "confused deputy" problem. The list of disallowed IP address ranges was lacking some IP address ranges that can be used to reach local IP addresses. An attacker can use an IP address in the affected ranges to make Mastodon perform HTTP requests against loopback or local network hosts, potentially allowing access to otherwise private resources and services. This is fixed in Mastodon v4.5.4, v4.4.11, v4.3.17 and v4.2.29.
CVSS 7.5
CVE-2026-22246 WRITEUP MEDIUM WRITEUP
Mastodon < 4.3.17 - Unauthenticated Information Disclosure via Severed Relationship Notifications
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 severed relationships for a particular event fails to check the owner of the list before returning the lost relationships. Any registered local user can access the list of lost followers and followed users caused by any severance event, and go through all severance events this way. The leaked information does not include the name of the account which has lost follows and followers. This has been fixed in Mastodon v4.3.17, v4.4.11 and v4.5.4.
CVSS 6.5
CVE-2023-36459 WRITEUP CRITICAL WRITEUP
Mastodon 1.3-3.5.8 - Stored Cross-Site Scripting via oEmbed Preview Card
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 1.3 and prior to versions 3.5.9, 4.0.5, and 4.1.3, an attacker using carefully crafted oEmbed data can bypass the HTML sanitization performed by Mastodon and include arbitrary HTML in oEmbed preview cards. This introduces a vector for cross-site scripting (XSS) payloads that can be rendered in the user's browser when a preview card for a malicious link is clicked through. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.
CVSS 9.3
CVE-2023-36460 WRITEUP CRITICAL WRITEUP
Mastodon <3.5.9, <4.0.5, <4.1.3 - Remote Code Execution
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 3.5.0 and prior to versions 3.5.9, 4.0.5, and 4.1.3, attackers using carefully crafted media files can cause Mastodon's media processing code to create arbitrary files at any location. This allows attackers to create and overwrite any file Mastodon has access to, allowing Denial of Service and arbitrary Remote Code Execution. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.
CVSS 9.9
CVE-2023-36461 WRITEUP HIGH WRITEUP
Mastodon < 3.5.9 - Denial of Service via Slowloris HTTP Response
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.
CVSS 7.5
CVE-2023-36462 WRITEUP MEDIUM WRITEUP
Mastodon 2.6.0-3.5.8 - URL Spoofing via Verified Profile Link Formatting
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, enabling it to appear to link to a different URL altogether. The link is visually misleading, but clicking on it will reveal the actual link. This can still be used for phishing, though, similar to IDN homograph attacks. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.
CVSS 5.4
CVE-2023-42450 WRITEUP MEDIUM WRITEUP
Mastodon 4.2.0-beta1 to 4.2.0-rc1 - HTTP Request Injection
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 to perform confused deputy attacks if the server configuration includes `ALLOWED_PRIVATE_ADDRESSES` to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.
CVSS 5.4
CVE-2023-42451 WRITEUP HIGH WRITEUP
Mastodon <3.5.14, <4.0.10, <4.1.8, <4.2.0-rc2 - Open Redirect
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. Versions 3.5.14, 4.0.10, 4.1.8, and 4.2.0-rc2 contain a patch for this issue.
CVSS 7.4
CVE-2023-42452 WRITEUP MEDIUM WRITEUP
Mastodon 4.0.0-4.0.9 - Cross-Site Scripting via 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 sanitization, allowing unescaped HTML to execute in the browser. The impact is limited thanks to Mastodon's strict Content Security Policy, blocking inline scripts, etc. However a CSP bypass or loophole could be exploited to execute malicious XSS. Furthermore, it requires user interaction, as this can only occur upon clicking the “Translate” button on a malicious post. Versions 4.0.10, 4.2.8, and 4.2.0-rc2 contain a patch for this issue.
CVSS 6.1
CVE-2024-23832 WRITEUP CRITICAL WRITEUP
Mastodon < 3.5.17, 4.0.x < 4.0.13, 4.1.x < 4.1.13, 4.2.x < 4.2.5 - Authentication Bypass via LDAP Origin Validation
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 Mastodon version prior to 3.5.17 is vulnerable, as well as 4.0.x versions prior to 4.0.13, 4.1.x version prior to 4.1.13, and 4.2.x versions prior to 4.2.5.
CVSS 9.4
CVE-2024-25618 WRITEUP MEDIUM WRITEUP
Mastodon < 3.5.18 - Account Takeover via External Authentication Provider Email Matching
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 account takeover if the authentication provider allows changing the e-mail address or multiple authentication providers are configured. When a user logs in through an external authentication provider for the first time, Mastodon checks the e-mail address passed by the provider to find an existing account. However, using the e-mail address alone means that if the authentication provider allows changing the e-mail address of an account, the Mastodon account can immediately be hijacked. All users logging in through external authentication providers are affected. The severity is medium, as it also requires the external authentication provider to misbehave. However, some well-known OIDC providers (like Microsoft Azure) make it very easy to accidentally allow unverified e-mail changes. Moreover, OpenID Connect also allows dynamic client registration. This issue has been addressed in versions 4.2.6, 4.1.14, 4.0.14, and 3.5.18. Users are advised to upgrade. There are no known workarounds for this vulnerability.
CVSS 4.2
CVE-2024-25619 WRITEUP LOW WRITEUP
Mastodon < 3.5.18 - Insufficient Session Expiration via OAuth Application Destruction
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 to continue listening to streaming after the application had been destroyed. Essentially this comes down to the fact that when Doorkeeper sets up the relationship between Applications and Access Tokens, it uses a `dependent: delete_all` configuration, which means the `after_commit` callback setup on `AccessTokenExtension` didn't actually fire, since `delete_all` doesn't trigger ActiveRecord callbacks. To mitigate, we need to add a `before_destroy` callback to `ApplicationExtension` which announces to streaming that all the Application's Access Tokens are being "killed". Impact should be negligible given the affected application had to be owned by the user. None the less this issue has been addressed in versions 4.2.6, 4.1.14, 4.0.14, and 3.5.18. Users are advised to upgrade. There are no known workaround for this vulnerability.
CVSS 3.1
CVE-2024-25623 WRITEUP HIGH WRITEUP
Mastodon <4.2.7, 4.1.15, 4.0.15, 3.5.19 - Info Disclosure
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 media type, which allows a threat actor to upload a crafted Activity Streams document to a remote server and make a Mastodon server fetch it, if the remote server accepts arbitrary user uploads. The vulnerability allows a threat actor to impersonate an account on a remote server that satisfies all of the following properties: allows the attacker to register an account; accepts arbitrary user-uploaded documents and places them on the same domain as the ActivityPub actors; and serves user-uploaded document in response to requests with an `Accept` header value of the Activity Streams media type. Versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19 contain a fix for this issue.
CVSS 8.5
CVE-2024-37903 WRITEUP HIGH WRITEUP
Mastodon 2.6.0-4.1.18 - Unauthorized Post Audience Extension via Crafted Activities
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 access to the contents of a post not intended for them. Versions 4.1.18 and 4.2.10 contain a patch for this issue.
CVSS 8.2
CVE-2024-47781 WRITEUP MEDIUM WRITEUP
CreateWiki >=2018-11-07 <2024-10-07 - Stored Cross-Site Scripting in Wiki Request Queue
CreateWiki is an extension used at Miraheze for requesting & creating wikis. The name of requested wikis is not escaped on Special:RequestWikiQueue, so a user can insert arbitrary HTML that is displayed in the request wiki queue when requesting a wiki. If a wiki creator comes across the XSS payload, their user session can be abused to retrieve deleted wiki requests, which typically contains private information. Likewise, this can also be abused on those with the ability to suppress requests to view sensitive information. This issue has been patched with commit `693a220` and all users are advised to apply the patch. Users unable to upgrade should disable Javascript and/or prevent access to the vulnerable page (Special:RequestWikiQueue).
CVSS 6.1
CVE-2024-47782 WRITEUP HIGH WRITEUP
WikiDiscover < 2024-10-06 - Stored Cross-Site Scripting in Special:WikiDiscover Page
WikiDiscover is an extension designed for use with a CreateWiki managed farm to display wikis. Special:WikiDiscover is a special page that lists all wikis on the wiki farm. However, the special page does not make any effort to escape the wiki name or description. Therefore, if a wiki sets its name and/or description to an XSS payload, the XSS will execute whenever the wiki is shown on Special:WikiDiscover. This issue has been patched with commit `2ce846dd93` and all users are advised to apply that patch. User unable to upgrade should block access to `Special:WikiDiscover`.
CVSS 7.6
CVE-2024-47812 WRITEUP MEDIUM WRITEUP
ImportDump - Stored Cross-Site Scripting in Special:RequestImportQueue Date Messages
ImportDump is an extension for mediawiki designed to automate user import requests. Anyone who can edit the interface strings of a wiki (typically administrators and interface admins) can embed XSS payloads in the messages for dates, and thus XSS anyone who views Special:RequestImportQueue. This issue has been patched in commit `d054b95` and all users are advised to apply this commit to their branch. Users unable to upgrade may either Prevent access to Special:RequestImportQueue on all wikis, except for the global wiki; and If an interface administrator (or equivalent) level protection is available (which is not provided by default) on the global wiki, protect the affected messages up to that level. This causes the XSS to be virtually useless as users with those rights can already edit Javascript pages. Or Prevent access to Special:RequestImportQueue altogether.
CVSS 6.0
CVE-2024-47815 WRITEUP MEDIUM WRITEUP
IncidentReporting - Authenticated Cross-Site Scripting
IncidentReporting is a MediaWiki extension for moving incident reports from wikitext to database tables. There are a variety of Cross-site Scripting issues, though all of them require elevated permissions. Some are available to anyone who has the `editincidents` right, some are available to those who can edit interface messages (typically administrators and interface admins), and one is available to those who can edit LocalSettings.php. These issues have been addressed in commit `43896a4` and all users are advised to upgrade. Users unable to upgrade should prevent access to the Special:IncidentReports page.
CVSS 6.0
CVE-2024-47816 WRITEUP MEDIUM WRITEUP
Mediawiki Extension - Info Disclosure
ImportDump is a mediawiki extension designed to automate user import requests. A user's local actor ID is stored in the database to tell who made what requests. Therefore, if a user on another wiki happens to have the same actor ID as someone on the central wiki, the user on the other wiki can act as if they're the original wiki requester. This can be abused to create new comments, edit the request, and view the request if it's marked private. This issue has been addressed in commit `5c91dfc` and all users are advised to update. Users unable to update may disable the special page outside of their global wiki. See `miraheze/mw-config@e566499` for details on that.
CVSS 6.4
CVE-2025-27157 WRITEUP MEDIUM WRITEUP
Mastodon <4.2.16-4.3.4 - Info Disclosure
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. Versions 4.2.16 and 4.3.4 fix the issue.
CVSS 5.3