{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-2454 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-2454 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-2454 is a medium-severity denial of service vulnerability in Mattermost Mattermost Server, published on 16 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-2454 and fix it if it is affected.\n\nWhat it is: CVE-2026-2454 is a medium-severity denial of service vulnerability in Mattermost Mattermost Server, published on 16 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-2454 in the wild and no public exploit code.\n\nAffected product: Mattermost Mattermost Server. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-2454/ (Markdown: https://insights.sbomify.com/CVE-2026-2454/index.md)","id":"CVE-2026-2454","markdown":"https://insights.sbomify.com/CVE-2026-2454/index.md","name":"CVE-2026-2454","record":{"aliases":["GHSA-3cx3-rw7f-7q37"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Mattermost Calls plugin","requires_auth":"none","summary":"A malicious user can crash the Mattermost server by sending malformed msgpack frames via websocket to the Calls plugin.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Mattermost","cpe":[{"product":"mattermost_server","vendor":"mattermost"}],"cvss":{"score":5.8,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L","version":"3.1"},"cwes":[{"id":"CWE-1287","name":"Improper Validation of Specified Type of Input"}],"description":"Mattermost versions 11.3.x \u003c= 11.3.0, 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10 fail to handle incorrectly reported array lengths which allows malicious user to cause OOM errors and crash the server via sending corrupted msgpack frames within websocket messages to calls plugin. Mattermost Advisory ID: MMSA-2025-00537","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"DoS in Calls plugin via malformed msgpack in websocket request.","id":"CVE-2026-2454","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mattermost:mattermost_server","products":["mattermost:mattermost_server"],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"SSRF bypass via IPv4-mapped IPv6 literals","id":"CVE-2026-2455"},"packages":[],"prev":{"headline":"Unsafe variable evaluation in email templates","id":"CVE-2026-2452"},"products":["Mattermost"],"published":"2026-03-16","related":[{"cvss_score":9.9,"headline":"Account takeover on OAuth/OpenID-enabled servers","id":"CVE-2025-12419","kev_date_added":null,"published":"2025-11-27"},{"cvss_score":9.9,"headline":"Account Takeover via Code Exchange Endpoint","id":"CVE-2025-12421","kev_date_added":null,"published":"2025-11-27"},{"cvss_score":9.9,"headline":"Path Traversal Leading to RCE by Any Authenticated Mattermost User","id":"CVE-2025-4981","kev_date_added":null,"published":"2025-06-20"},{"cvss_score":9.9,"headline":"Arbitrary file read via block duplication in Mattermost Boards","id":"CVE-2025-20051","kev_date_added":null,"published":"2025-02-24"},{"cvss_score":9.9,"headline":"Arbitrary file read in Mattermost Boards via import \u0026 export board archive","id":"CVE-2025-25279","kev_date_added":null,"published":"2025-02-24"},{"cvss_score":9.8,"headline":"Mattermost Server: Insufficient Password-Reset Link Invalidation","id":"CVE-2016-11074","kev_date_added":null,"published":"2020-06-19"},{"cvss_score":9.8,"headline":"Mattermost Server allows attackers to gain privileges by accessing unintended API endpoints with users' credentials","id":"CVE-2017-18885","kev_date_added":null,"published":"2020-06-19"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-03-17","vendors":["Mattermost"]},"summary":"A malicious user can crash the Mattermost server by sending malformed msgpack frames via websocket to the Calls plugin.","url":"https://insights.sbomify.com/CVE-2026-2454/"}