{"answers":{"affected":"17 open source packages ship an affected version, including github.com/mattermost/mattermost-server, github.com/mattermost/mattermost-server/v5 and github.com/mattermost/mattermost-server/v6. It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-13821 in the wild and no public exploit code.","fix":"Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20251210191531-cd17b61de41b or later.","what":"CVE-2025-13821 is a medium-severity vulnerability in Mattermost Mattermost Server, published on 16 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2025-13821 and fix it if it is affected.\n\nWhat it is: CVE-2025-13821 is a medium-severity vulnerability in Mattermost Mattermost Server, published on 16 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2025-13821 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- github.com/mattermost/mattermost-server (Go): affected all versions; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected all versions; fixed in 5.3.2-0.20251210191531-cd17b61de41b\n- github.com/mattermost/mattermost-server (Go): affected all versions; fixed in 5.3.2-0.20251210191531-cd17b61de41b\n- github.com/mattermost/mattermost-server (Go): affected from 10.11.0; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected from 10.11.0; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected from 10.11.0+incompatible; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected from 11.1.0; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected from 11.1.0; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected from 11.1.0+incompatible; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected from 11.2.0; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected from 11.2.0; no fix listed\n- github.com/mattermost/mattermost-server (Go): affected from 11.2.0+incompatible; no fix listed\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-2025-13821/ (Markdown: https://insights.sbomify.com/CVE-2025-13821/index.md)","id":"CVE-2025-13821","markdown":"https://insights.sbomify.com/CVE-2025-13821/index.md","name":"CVE-2025-13821","record":{"aliases":["GHSA-pp9j-pf5c-659x","GO-2026-4524"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"Mattermost chat platform","requires_auth":"low_privilege","summary":"Authenticated users can exfiltrate password hashes and MFA secrets via unsanitized WebSocket messages in Mattermost.","user_interaction":"required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Mattermost","cpe":[{"product":"mattermost_server","vendor":"mattermost"}],"cvss":{"score":5.7,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-200","name":"Exposure of Sensitive Information to an Unauthorized Actor"}],"description":"Mattermost versions 11.1.x \u003c= 11.1.2, 10.11.x \u003c= 10.11.9, 11.2.x \u003c= 11.2.1 fail to sanitize sensitive data in WebSocket messages which allows authenticated users to exfiltrate password hashes and MFA secrets via profile nickname updates or email verification events. Mattermost Advisory ID: MMSA-2025-00560","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"User profile update exposes password hash and MFA secrets","id":"CVE-2025-13821","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":"mattermost:mattermost_server","products":["mattermost:mattermost_server"],"type":"information_disclosure","year":"2025"},"n_packages":17,"n_references":1,"next":{"headline":"Authentication bypass in MCPHub","id":"CVE-2025-13822"},"packages":[{"ecosystem":"Go","fixed":[],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GO-2026-4524"},{"ecosystem":"Go","fixed":["5.3.2-0.20251210191531-cd17b61de41b"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":["5.3.2-0.20251210191531-cd17b61de41b"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":[],"introduced":["10.11.0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":[],"introduced":["10.11.0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":[],"introduced":["10.11.0+incompatible"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GO-2026-4524"},{"ecosystem":"Go","fixed":[],"introduced":["11.1.0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":[],"introduced":["11.1.0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":[],"introduced":["11.1.0+incompatible"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GO-2026-4524"},{"ecosystem":"Go","fixed":[],"introduced":["11.2.0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":[],"introduced":["11.2.0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":[],"introduced":["11.2.0+incompatible"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GO-2026-4524"},{"ecosystem":"Go","fixed":[],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server/v5","purl":"pkg:golang/github.com/mattermost/mattermost-server/v5","source":"GO-2026-4524"},{"ecosystem":"Go","fixed":[],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server/v6","purl":"pkg:golang/github.com/mattermost/mattermost-server/v6","source":"GO-2026-4524"},{"ecosystem":"Go","fixed":["8.0.0-20251210191531-cd17b61de41b"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost/server/v8","purl":null,"source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":["8.0.0-20251210191531-cd17b61de41b"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","source":"GHSA-pp9j-pf5c-659x"},{"ecosystem":"Go","fixed":["8.0.0-20251210191531-cd17b61de41b"],"introduced":["0"],"last_affected":[],"package":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","source":"GO-2026-4524"}],"prev":{"headline":"Comments – wpDiscuz \u003c 7.6.40 - Unauthenticated Account Takeover","id":"CVE-2025-13820"},"products":["Mattermost"],"published":"2026-02-16","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":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"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":"2026-02-17","vendors":["Mattermost"]},"summary":"Authenticated users can exfiltrate password hashes and MFA secrets via unsanitized WebSocket messages in Mattermost.","url":"https://insights.sbomify.com/CVE-2025-13821/"}