{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-19076 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-19076 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-19076 is a medium-severity authentication bypass vulnerability in Mattermost Mattermost Server, published on 16 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-19076 and fix it if it is affected.\n\nWhat it is: CVE-2026-19076 is a medium-severity authentication bypass vulnerability in Mattermost Mattermost Server, published on 16 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-19076 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-2026-19076/ (Markdown: https://insights.sbomify.com/CVE-2026-19076/index.md)","id":"CVE-2026-19076","markdown":"https://insights.sbomify.com/CVE-2026-19076/index.md","name":"CVE-2026-19076","record":{"aliases":["GHSA-hhjm-mg95-jr6g"],"analysis":{"component_type":"web_application","fix_type":"patch","impacts":["account_takeover"],"network_reachable":"yes","non_default_config":false,"product_category":"Mattermost collaboration platform","requires_auth":"high_privilege","summary":"Attackers with valid OAuth tokens can take over SSO accounts by bypassing account type switch restrictions in Mattermost.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Mattermost","cpe":[{"product":"mattermost_server","vendor":"mattermost"}],"cvss":{"score":4.4,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-863","name":"Incorrect Authorization"}],"description":"Mattermost versions 11.10.x \u003c= 11.10.0, 11.7.x \u003c= 11.7.9, 11.9.x \u003c= 11.9.1, 11.8.x \u003c= 11.8.5 fail to reject OAuth application sessions in the account type switch endpoint, which allows an attacker with a valid OAuth bearer token for a target user to permanently take over that user's SSO-backed account by setting an attacker-controlled password and detaching the account from its identity provider via a crafted request to POST /api/v4/users/login/switch.. Mattermost Advisory ID: MMSA-2026-00758","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":"Auth bypass in Mattermost","id":"CVE-2026-19076","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mattermost:mattermost_server","products":["mattermost:mattermost_server"],"type":"auth_bypass","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"Copy \u0026 Delete Posts \u003c 1.5.5 - Authenticated Arbitrary Post Deletion via Missing Object-Level Authorization","id":"CVE-2026-19077"},"packages":[],"prev":{"headline":"All-in-One Video Gallery \u003c 4.9.2 - Subscriber+ Server-Side Request Forgery via 'vdl' Parameter","id":"CVE-2026-19075"},"products":["Mattermost"],"published":"2026-10-16","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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-16","vendors":["Mattermost"]},"summary":"Attackers with valid OAuth tokens can take over SSO accounts by bypassing account type switch restrictions in Mattermost.","url":"https://insights.sbomify.com/CVE-2026-19076/"}