{"id":"CVE-2026-49256","aliases":["BIT-discourse-2026-49256","EUVD-2026-42730","GHSA-mwp7-572g-6qpx"],"status":"published","title":"Discourse: Hidden tag names leaked via category serializers","description":"Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.","severity":{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00508,"percentile":0.43704,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-200"],"published":"2026-07-09T21:56:40Z","modified":"2026-10-28T02:31:05Z","fixes":[{"ecosystem":"Bitnami","package":"discourse","fixed_in":["2026.1.5","2026.4.2","2026.5.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"discourse","ranges":[{"type":"SEMVER","events":[{"introduced":"2026.1.0"},{"fixed":"2026.1.5"},{"introduced":"2026.4.0"},{"fixed":"2026.4.2"},{"introduced":"2026.5.0"},{"fixed":"2026.5.1"}]}]}],"products":[{"vendor":"discourse","product":"discourse"}],"references":[{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-mwp7-572g-6qpx","tags":["x_refsource_CONFIRM","Vendor Advisory","Mitigation","advisory"]},{"url":"https://github.com/discourse/discourse/releases/tag/v2026.1.5","tags":["x_refsource_MISC","Release Notes","Patch","fix","web"]},{"url":"https://github.com/discourse/discourse/releases/tag/v2026.4.2","tags":["x_refsource_MISC","Release Notes","article","web"]},{"url":"https://github.com/discourse/discourse/releases/tag/v2026.5.1","tags":["x_refsource_MISC","Release Notes","article","web"]},{"url":"https://github.com/discourse/discourse/releases/tag/v2026.6.0","tags":["x_refsource_MISC","Release Notes","article","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49256","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49256.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-49256","title":"Discourse: Hidden tag names leaked via category serializers","description":"Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.","status":"published","published":"2026-07-09T21:56:40.444Z","modified":"2026-07-10T13:39:27.829Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T13:35:10.963527Z"}],"euvd":[{"id":"EUVD-2026-42730","description":"Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.","status":"published","published":"2026-07-09T21:56:40Z","modified":"2026-07-10T13:39:27Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:20:03.345658Z"}],"nvd":[{"id":"CVE-2026-49256","description":"Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.","status":"published","published":"2026-07-09T22:17:05.26Z","modified":"2026-07-14T20:40:56.59Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"primary"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:12:28.4135Z"}],"osv":[{"id":"CVE-2026-49256","title":"Discourse: Hidden tag names leaked via category serializers","description":"Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.","status":"published","published":"2026-07-09T21:56:40.444Z","modified":"2026-10-28T02:31:05.741683367Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T15:45:07.060148Z"},{"id":"BIT-discourse-2026-49256","title":"Discourse: Hidden tag names leaked via category serializers","description":"Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.","status":"published","published":"2026-07-15T15:56:20.616Z","modified":"2026-09-10T16:00:58.746682944Z","updated_at":"2026-11-02T15:28:29.152062Z"}]}}