Improper input handling in a system endpoint may allow attackers to overload resources, causing a denial of service.

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to limit the size of the request body on the start meeting API endpoint, which allows an authenticated attacker to cause resource exhaustion or denial of service via a crafted oversized HTTP POST request to {{/api/v1/meetings}}.. Mattermost Advisory ID: MMSA-2026-00608

A Vulnerability has been found in PowerDNS Authoritative Server before versions 4.1.9, 4.0.8 allowing a remote, authorized master server to cause a high CPU load or even prevent any further updates to any slave zone by sending a large number of NOTIFY messages. Note that only servers configured as slaves are affected by this issue.

FreshRSS is a free, self-hostable RSS aggregator. From version 1.27.0 to before 1.28.0, An attacker could globally deny access to feeds via proxy modifying to 429 Retry-After for a large list of feeds on given instance, making it unusable for majority of users. This issue has been patched in version 1.28.0.

Discourse is an open source discussion platform. Versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0 have an application level denial of service vulnerabilityin the username change functionality at try.discourse.org. The vulnerability allows attackers to cause noticeable server delays and resource exhaustion by sending large JSON payloads to the username preference endpoint PUT /u//preferences/username, resulting in degraded performance for other users and endpoints. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. No known workarounds are available.

Mattermost versions 10.11.x <= 10.11.8 fail to validate input size before processing hashtags which allows an authenticated attacker to exhaust CPU resources via a single HTTP request containing a post with thousands space-separated tokens

An issue was discovered in GitLab CE/EE affecting all versions starting from 13.9 before 17.4.6, 17.5 before 17.5.4, and 17.6 before 17.6.2, that allows an attacker to cause uncontrolled CPU consumption, potentially leading to a Denial of Service (DoS) condition while parsing templates to generate changelogs.

Jetty PushSessionCacheFilter can be exploited by unauthenticated users to launch remote DoS attacks by exhausting the server’s memory.

Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1 and 9.5.x <= 9.5.9 fail to prevent detailed error messages from being displayed in Playbooks which allows an attacker to generate a large response and cause an amplified GraphQL response which in turn could cause the application to crash by sending a specially crafted request to Playbooks.

An issue has been discovered in GitLab CE/EE affecting all versions starting from 15.4 prior to 16.9.7, starting from 16.10 prior to 16.10.5, and starting from 16.11 prior to 16.11.2 where abusing the API to filter branch and tags could lead to Denial of Service.

Using a densely populated chars mask and a large input string in the MongoDB aggregation operators $trim, $ltrim, and $rtrim, an authenticated user with aggregation permissions can pin CPU utilization at 100% for an extended period of time. This issue impacts MongoDB Server v7.0 versions prior to 7.0.34, v8.0 versions prior to 8.0.23, v8.2 versions prior to 8.2.9 and v8.3 versions prior to 8.3.2.

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.

OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.

OpenClaw before 2026.3.31 contains a resource exhaustion vulnerability in media downloads that bypasses core safety limits for file size, count, and cleanup operations. Attackers can exhaust disk space by downloading media files without triggering intended safety restrictions, causing availability impact.

IBM Aspera Shares 1.9.0 through 1.10.0 PL6 does not properly rate limit the frequency that an authenticated user can send emails, which could result in email flooding or a denial of service.

An issue was discovered in GitLab CE/EE affecting all versions starting from 17.2 before 18.2.7, 18.3 before 18.3.3, and 18.4 before 18.4.1, that allows an attacker to cause uncontrolled CPU consumption, potentially leading to a Denial of Service (DoS) condition while using specific GraphQL queries.

discourse-calendar is a discourse plugin which adds the ability to create a dynamic calendar in the first post of a topic. The limit on region value length is too generous. This allows a malicious actor to cause a Discourse instance to use excessive bandwidth and disk space. This issue has been patched in main the main branch. There are no workarounds for this vulnerability. Please upgrade as soon as possible.

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

A denial-of-service vulnerability in the Mattermost Playbooks plugin allows an authenticated user to crash the server via multiple large requests to one of the Playbooks API endpoints.