{"id":"CVE-2026-50053","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-50053","generatedAt":"2026-10-28T03:32:36.822Z","title":"A request attribute override vulnerability in Zimbra Collaboration Suite (ZCS) allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch.","description":"A request attribute override vulnerability in Zimbra Collaboration Suite (ZCS) allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch. RestFilter copies URL parameters specifying an authentication token, target account, target item and dispatch state into the request attributes consumed by the Classic Web Client. Combined with CVE-2026-10632 on ZCS 10.1.16, this allows an attacker to supply their own valid token and document identifiers and execute JavaScript in another user's signed-in browser session. ZCS 10.1.17 blocks that XSS chain by changing the document renderer, but retains the request attribute override.","published":"2026-10-23T14:17:53.000Z","lastModified":"2026-10-23T16:44:18.000Z","status":"Awaiting Analysis","sourceIdentifier":"cve@rapid7.com","cvss":{"version":"3.1","score":8.7,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N"},"cwe":["CWE-642"],"affected":[],"epss":{"score":0.00301,"percentile":0.2274,"date":"2026-10-27","history":[{"date":"2026-10-24","score":0.00424,"percentile":0.3564}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-23T14:17:53.000Z","detail":{"score":"8.7","severity":"HIGH","publishedAt":"2026-10-23T14:17:53.060Z"},"summary":"New CVE, high severity (CVSS 8.7)."}],"references":[{"url":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories","source":"cve@rapid7.com"},{"url":"https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/","source":"cve@rapid7.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-50053","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}