{"id":"CVE-2026-113728","title":"Bulwark Webmail: DNS-rebinding SSRF in public iCalendar fetch endpoint","summary":"Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.9.2, the unauthenticated POST /api/fetch-ical endpoint validates a caller-supplied hostname with one DNS lookup and then passes the URL to fetch, which …","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cvssSource":"cna","cwe":["CWE-918"],"vendor":"bulwarkmail","product":"webmail","affected":["webmail < 1.9.2"],"published":"2026-10-20","updated":"2026-10-20","sourceUpdated":"2026-10-20T21:12:38.182Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-113728","references":[{"url":"https://github.com/bulwarkmail/webmail/security/advisories/GHSA-24w9-8r42-8jwm","label":"https://github.com/bulwarkmail/webmail/security/advisories/GHSA-24w9-8r42-8jwm"},{"url":"https://github.com/bulwarkmail/webmail/commit/3288589e5248dcc1da769cc578827a9ee1adc941","label":"https://github.com/bulwarkmail/webmail/commit/3288589e5248dcc1da769cc578827a9ee1adc941"},{"url":"https://github.com/bulwarkmail/webmail/releases/tag/1.9.2","label":"https://github.com/bulwarkmail/webmail/releases/tag/1.9.2"}],"tags":["cve.org"],"ingestedAt":"2026-10-20T21:19:21.147Z","slug":"CVE-2026-113728","body":"## Overview\n\nBulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.9.2, the unauthenticated POST /api/fetch-ical endpoint validates a caller-supplied hostname with one DNS lookup and then passes the URL to fetch, which performs a separate lookup for the socket connection. An attacker controlling authoritative DNS can return a public address during validation and then rebind the hostname to a loopback, private, link-local, or cloud metadata address for the connection, causing the server to return up to 10 MB of an internal HTTP or HTTPS response. The same check-then-fetch pattern also existed in authenticated JMAP login and TOTP token-exchange flows. This issue is fixed in version 1.9.2.\n\n## Affected\n\n- `webmail < 1.9.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}