{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-96259 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-96259 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-96259 is a medium-severity server-side request forgery vulnerability in Mattermost Mattermost Server, published on 22 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-96259 and fix it if it is affected.\n\nWhat it is: CVE-2026-96259 is a medium-severity server-side request forgery vulnerability in Mattermost Mattermost Server, published on 22 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-96259 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-2026-96259/ (Markdown: https://insights.sbomify.com/CVE-2026-96259/index.md)","id":"CVE-2026-96259","markdown":"https://insights.sbomify.com/CVE-2026-96259/index.md","name":"CVE-2026-96259","record":{"aliases":["GHSA-j85c-qqpv-57m3"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Mattermost server","requires_auth":"high_privilege","summary":"A System Administrator can exploit missing internal connection filters in OAuth endpoints to perform server-side request forgery and read internal network responses.","user_interaction":"not_required","vuln_class":"ssrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Mattermost","cpe":[{"product":"mattermost_server","vendor":"mattermost"}],"cvss":{"score":5.5,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-918","name":"Server-Side Request Forgery"}],"description":"Mattermost versions 11.9.x \u003c= 11.9.1, 11.8.x \u003c= 11.8.5, 11.7.x \u003c= 11.7.10, 11.10.x \u003c= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776","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":"Mattermost server-side request forgery via OAuth endpoints configurable by a System Administrator","id":"CVE-2026-96259","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mattermost:mattermost_server","products":["mattermost:mattermost_server"],"type":"ssrf","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"Mattermost server missing request body size limit on plugin routes allows denial of service by an authenticated user","id":"CVE-2026-96260"},"packages":[],"prev":{"headline":"onSite internet GmbH Auktion NG Auktionssoftware Public Password Reset Endpoint forgotpasswd.html cross site scripting","id":"CVE-2026-96258"},"products":["Mattermost"],"published":"2026-09-22","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":"2026-09-23","vendors":["Mattermost"]},"summary":"A System Administrator can exploit missing internal connection filters in OAuth endpoints to perform server-side request forgery and read internal network responses.","url":"https://insights.sbomify.com/CVE-2026-96259/"}