Mattermost Mobile app versions 2.13.0 and earlier use a regular expression with polynomial complexity to parse certain deeplinks, which allows an unauthenticated remote attacker to freeze or crash the app via a long maliciously crafted link.

Mattermost Desktop App versions <= 5.13.0 fail to validate URLs external to the configured Mattermost servers, allowing an attacker on a server the user has configured to crash the user's application by sending the user a malformed URL.

An issue was discovered in Mattermost Server before 5.14.0, 5.13.3, 5.12.6, and 5.9.4. It allows remote attackers to cause a denial of service (application hang) via a crafted SVG document.

An issue was discovered in Mattermost Server before 1.2.0. It allows attackers to cause a denial of service (memory consumption) via a small compressed file that has a large size when uncompressed.

Mattermost version 7.1.x and earlier fails to sufficiently process a specifically crafted GIF file when it is uploaded while drafting a post, which allows authenticated users to cause resource exhaustion while processing the file, resulting in server-side Denial of Service.

Mattermost Plugin Channel Export versions <=1.0.0 fail to restrict concurrent runs of the /export command which allows a user to consume excessive resource by running the /export command multiple times at once.

Mattermost versions 8.1.x before 8.1.12, 9.6.x before 9.6.1, 9.5.x before 9.5.3, 9.4.x before 9.4.5 fail to limit the number of active sessions, which allows an authenticated attacker to crash the server via repeated requests to the getSessions API after flooding the sessions table.

Mattermost version 7.0.x and earlier fails to sufficiently limit the in-memory sizes of concurrently uploaded JPEG images, which allows authenticated users to cause resource exhaustion on specific system configurations, resulting in server-side Denial of Service.

Mattermost fails to properly sanitize the request to /api/v4/redirect_location allowing an attacker, sending a specially crafted request to /api/v4/redirect_location, to fill up the memory due to caching large items.

Mattermost fails to properly validate a RegExp built off the server URL path, allowing an attacker in control of an enrolled server to mount a Denial Of Service.

Mattermost Mobile fails to limit the maximum number of Markdown elements in a post allowing an attacker to send a post with hundreds of emojis to a channel and freeze the mobile app of users when viewing that particular channel. 

Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.

Mattermost fails to enforce a limit for the size of the cache entry for OpenGraph data allowing an attacker to send a specially crafted request to the /api/v4/opengraph filling the cache and turning the server unavailable.

Mattermost versions 9.5.x <= 9.5.7 and 9.10.x <= 9.10.0 fail to time limit and size limit the CA path file in the ElasticSearch configuration which allows a System Role with access to the Elasticsearch system console to add any file as a CA path field, such as /dev/zero and, after testing the connection, cause the application to crash.

Mattermost fails to enforce character limits in all possible notification props allowing an attacker to send a really long value for a notification_prop resulting in the server consuming an abnormal quantity of computing resources and possibly becoming temporarily unavailable for its users.

Mattermost fails to limit the amount of data extracted from compressed archives during board import in Mattermost Boards allowing an attacker to consume excessive resources, possibly leading to Denial of Service, by importing a board using a specially crafted zip (zip bomb).

Mattermost versions 9.11.x <= 9.11.0 and 9.5.x <= 9.5.8 fail to validate that the message of the permalink post is a string, which allows an attacker to send a non-string value as the message of a permalink post and crash the frontend.

Mattermost fails to properly limit the characters allowed in different fields of a block in Mattermost Boards allowing a attacker to consume excessive resources, possibly leading to Denial of Service, by patching the field of a block using a specially crafted string. 

Mattermost Boards fail to properly validate a board link, allowing an attacker to crash a channel by posting a specially crafted boards link.

Mattermost fails to properly validate a gif image file, allowing an attacker to consume a significant amount of server resources, making the server unresponsive for an extended period of time by linking to specially crafted image file.

The legacy Slack import feature in Mattermost version 6.7.0 and earlier fails to properly limit the sizes of imported files, which allows an authenticated attacker to crash the server by importing large files via the Slack import REST API.

Mattermost Server versions 9.5.x before 9.5.2, 9.4.x before 9.4.4, 9.3.x before 9.3.3, 8.1.x before 8.1.11 don't limit the number of user preferences which allows an attacker to send a large number of user preferences potentially causing denial of service.

Resource Exhaustion in Mattermost Server versions 8.1.x before 8.1.10 fails to limit the size of the payload that can be read and parsed allowing an attacker to send a very large email payload and crash the server.

Uncontrolled resource consumption in Mattermost version 6.6.0 and earlier allows an authenticated attacker to crash the server via a crafted SVG attachment on a post.

The image proxy component in Mattermost version 6.4.1 and earlier allocates memory for multiple copies of a proxied image, which allows an authenticated attacker to crash the server via links to very large image files.

Uncontrolled Resource Consumption in Mattermost Mobile versions before 2.13.0 fails to limit the size of the code block that will be processed by the syntax highlighter, allowing an attacker to send a very large code block and crash the mobile app.

Mattermost fails to properly validate the length of the emoji value in the custom user status, allowing an attacker to send multiple times a very long string as an emoji value causing high resource consumption and possibly crashing the server.

Mattermost versions 8.1.x before 8.1.10, 9.2.x before 9.2.6, 9.3.x before 9.3.2, and 9.4.x before 9.4.3 fail to limit the number of @-mentions processed per message, allowing an authenticated attacker to crash the client applications of other users via large, crafted messages.

Mattermost versions 8.1.x <= 8.1.10, 9.6.x <= 9.6.0, 9.5.x <= 9.5.2 and 8.1.x <= 8.1.11 fail to limit the size of a request path that includes user inputs which allows an attacker to cause excessive resource consumption, possibly leading to a DoS via sending large request paths

Mattermost fails to validate links on external websites when constructing a preview for a linked website, allowing an attacker to cause a denial-of-service by a linking to a specially crafted webpage in a message.

Mattermost fails to unescape Markdown strings in a memory-efficient way, allowing an attacker to cause a Denial of Service by sending a message containing a large number of escaped characters.

Mattermost versions 8.1.x before 8.1.9, 9.2.x before 9.2.5, 9.3.0, and 9.4.x before 9.4.2 fail to limit the number of role names requested from the API, allowing an authenticated attacker to cause the server to run out of memory and crash by issuing an unusually large HTTP request.

Mattermost fails to check if a custom emoji reaction exists when sending it to a post and to limit the amount of custom emojis allowed to be added in a post, allowing an attacker sending a huge amount of non-existent custom emojis in a post to crash the mobile app of a user seeing the post and to crash the server due to overloading when clients attempt to retrive the aforementioned post. 

Mattermost 6.2 and earlier fails to sufficiently process a specifically crafted GIF file when it is uploaded while drafting a post, which allows authenticated users to cause resource exhaustion while processing the file, resulting in server-side Denial of Service.

Mattermost fails to handle a null request body in the /add endpoint, allowing a simple member to send a request with null request body to that endpoint and make it crash. After a few repetitions, the plugin is disabled. 

Mattermost fails to limit the log size of server logs allowing an attacker sending specially crafted requests to different endpoints to potentially overflow the log.

Mattermost fails to to check the length when setting the title in a run checklist in Playbooks, allowing an attacker to send a specially crafted request and crash the Playbooks plugin

An issue was discovered in Mattermost Server before 5.15.0. It allows attackers to cause a denial of service (CPU consumption) via crafted characters in a SQL LIKE clause to an APIv4 endpoint.

Mattermost fails to properly truncate the postgres error log message of a search query failure allowing an attacker to cause the creation of large log files which can result in Denial of Service

Mattermost fails to properly validate markdown, allowing an attacker to crash the server via a specially crafted markdown input.

A remote denial-of-service vulnerability exists in the way the Nouveau Display Driver (the default Ubuntu Nvidia display driver) handles GPU shader execution. A specially crafted pixel shader can cause remote denial-of-service issues. An attacker can provide a specially crafted website to trigger this vulnerability. This vulnerability can be triggered remotely after the user visits a malformed website. No further user interaction is required. Vulnerable versions include Ubuntu 18.04 LTS (linux 4.15.0-29-generic x86_64), Nouveau Display Driver NV117 (vermagic: 4.15.0-29-generic SMP mod_unload).

A resource exhaustion issue was addressed with improved input validation. This issue is fixed in tvOS 12.1, iOS 12.1. Processing a maliciously crafted message may lead to a denial of service.

SheetJS and SheetJS Pro through 0.16.9 allows attackers to cause a denial of service (CPU consumption) via a crafted .xlsx document that is mishandled when read by xlsx.js.

Prism is a syntax highlighting library. Some languages before 1.24.0 are vulnerable to Regular Expression Denial of Service (ReDoS). When Prism is used to highlight untrusted (user-given) text, an attacker can craft a string that will take a very very long time to highlight. This problem has been fixed in Prism v1.24. As a workaround, do not use ASCIIDoc or ERB to highlight untrusted text. Other languages are not affected and can be used to highlight untrusted text.

In the bindata RubyGem before version 2.4.10 there is a potential denial-of-service vulnerability. In affected versions it is very slow for certain classes in BinData to be created. For example BinData::Bit100000, BinData::Bit100001, BinData::Bit100002, BinData::Bit<N>. In combination with <user_input>.constantize there is a potential for a CPU-based DoS. In version 2.4.10 bindata improved the creation time of Bits and Integers.

An issue was discovered in Bento4 1.5.1-627. There is an attempt at excessive memory allocation in the AP4_DataBuffer class when called from AP4_HvccAtom::Create in Core/Ap4HvccAtom.cpp.

SheetJS and SheetJS Pro through 0.16.9 allows attackers to cause a denial of service (memory consumption) via a crafted .xlsx document that is mishandled when read by xlsx.js (issue 2 of 2).

There is an attempted excessive memory allocation at libxsmm_sparse_csc_reader in generator_spgemm_csc_reader.c in LIBXSMM 1.10 that will cause a denial of service.

In Artifex MuPDF 1.14.0, svg/svg-run.c allows remote attackers to cause a denial of service (recursive calls followed by a fitz/xml.c fz_xml_att crash from excessive stack consumption) via a crafted svg file, as demonstrated by mupdf-gl.

In LibSass prior to 3.5.5, Sass::Eval::operator()(Sass::Binary_Expression*) inside eval.cpp allows attackers to cause a denial-of-service resulting from stack consumption via a crafted sass file, because of certain incorrect parsing of '%' as a modulo operator in parser.cpp.