CVE-2026-113728
Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server
- Risk score
- 59/100
- CVSS
- 7.5 v3.1
- Exploit chance (30 days)
- 0.5%
- Published
- 20 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 performs a separate lookup for the socket connection. An attacker controlling auth…
- Affected
- See advisory
- Fix
- Upgrade the product to 1.9.2 or later.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 7.5 high
- Remotely exploitable without logging in
References
Original description
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 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.
Last activity 20 Oct 2026. Patch Forecast updates every hour.