{"answers":{"affected":"1 open source package ship an affected version, including discourse. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-31869 in the wild and no public exploit code.","fix":"Upgrade discourse to a fixed version for your release line: 2026.1.2, 2026.2.1 or 2026.3.0.","what":"CVE-2026-31869 is a medium-severity vulnerability in Discourse Discourse, published on 20 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-31869 and fix it if it is affected.\n\nWhat it is: CVE-2026-31869 is a medium-severity vulnerability in Discourse Discourse, published on 20 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-31869 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- discourse (Bitnami): affected from 2026.1.0; fixed in 2026.1.2, 2026.2.1, 2026.3.0\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-2026-31869/ (Markdown: https://insights.sbomify.com/CVE-2026-31869/index.md)","id":"CVE-2026-31869","markdown":"https://insights.sbomify.com/CVE-2026-31869/index.md","name":"CVE-2026-31869","record":{"aliases":["BIT-discourse-2026-31869","GHSA-5f9h-vp7v-7vq5"],"analysis":{"component_type":"web_application","fix_type":"patch","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Discourse forum platform","requires_auth":"low_privilege","summary":"Authenticated attackers can infer hidden group membership in Discourse by probing the mentions endpoint, bypassing visibility controls.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"discourse","vendor":"discourse"}],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-639","name":"Authorization Bypass Through User-Controlled Key"},{"id":"CWE-285","name":"Improper Authorization"},{"id":"CWE-200","name":"Exposure of Sensitive Information to an Unauthorized Actor"}],"description":"Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the ComposerController#mentions endpoint reveals hidden group membership to any authenticated user who can message the group. By supplying allowed_names referencing a hidden-membership group and probing arbitrary usernames, an attacker can infer membership based on whether user_reasons returns \"private\" for a given user. This bypasses group member-visibility controls. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. To work around this issue, restrict the messageable policy of any hidden-membership group to staff or group members only, so untrusted users cannot reach the vulnerable code path.","ecosystems":["Bitnami"],"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":"Discourse: Composer mentions endpoint leaks hidden group membership through PM `allowed_names` check","id":"CVE-2026-31869","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":"discourse:discourse","products":["discourse:discourse"],"type":"information_disclosure","year":"2026"},"n_packages":1,"n_references":1,"next":{"headline":"cpp-httplib Affected by Remote Process Crash via Malformed Content-Length Response Header","id":"CVE-2026-31870"},"packages":[{"ecosystem":"Bitnami","fixed":["2026.1.2","2026.2.1","2026.3.0"],"introduced":["2026.1.0","2026.2.0","2026.3.0"],"last_affected":[],"package":"discourse","purl":"pkg:bitnami/discourse","source":"BIT-discourse-2026-31869"}],"prev":{"headline":"Parse Server has Stored XSS via file upload of HTML-renderable file types","id":"CVE-2026-31868"},"products":["discourse"],"published":"2026-03-20","related":[{"cvss_score":10,"headline":"RCE via malicious SNS subscription payload","id":"CVE-2021-41163","kev_date_added":null,"published":"2021-10-20"},{"cvss_score":9.1,"headline":"Discourse vulnerable to RCE via admins uploading maliciously zipped file","id":"CVE-2022-36066","kev_date_added":null,"published":"2022-09-29"},{"cvss_score":8.9,"headline":"Discourse user account takeover via email and invite link","id":"CVE-2022-39356","kev_date_added":null,"published":"2022-11-02"},{"cvss_score":8.8,"headline":"Discourse vulnerable to Cross-site Scripting in local oneboxes","id":"CVE-2023-22468","kev_date_added":null,"published":"2023-01-26"},{"cvss_score":8.7,"headline":"Discourse leaks private topic title and post excerpt via user action API endpoint","id":"CVE-2026-27934","kev_date_added":null,"published":"2026-03-19"},{"cvss_score":8.7,"headline":"Discourse vulnerable to DoS via large URL payload in PM to a bot","id":"CVE-2025-48053","kev_date_added":null,"published":"2025-06-09"},{"cvss_score":8.6,"headline":"Discourse vulnerable to unlimited mentioned users in message serializer","id":"CVE-2023-48297","kev_date_added":null,"published":"2024-01-12"}],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"Bitnami","prefix":"BIT"},{"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":"2026-03-20","vendors":["discourse"]},"summary":"Authenticated attackers can infer hidden group membership in Discourse by probing the mentions endpoint, bypassing visibility controls.","url":"https://insights.sbomify.com/CVE-2026-31869/"}