Files
openmail/SECURITY.md
T
Karti TripathiandClaude Opus 5 36b15ddcaf Rewrite as a Rust, Apache-2.0 workspace
Supersedes the Go + embed-Mox design. The Go tree is removed; its
architecture doc is preserved at docs/archive/ARCHITECTURE-go-embed-mox.md
because its competitive analysis and data model still hold.

Five decisions recorded as ADRs:

  0001  Rust, not Go — accepting ~5,500 lines of protocol code that Mox
        would have given us free, to get the first permissively licensed
        Rust mail server. Costs stated plainly.
  0002  Apache-2.0, not MIT or AGPL — patent grant, trademark, CLA-free
        contribution. Public on GitHub; Gitea stays as the private fallback.
  0003  Stalwart's primitive crates (Apache-2.0/MIT) yes; its AGPL server
        crates never. DANE and MTA-STS sit on the AGPL side of that line,
        which is why we write our own.
  0004  Milestones, reordered: embedded inbound is required at launch.
  0005  Oracle Cloud blocks outbound :25, so direct-to-MX is impossible on
        the launch host. Split delivery is mandatory, not an on-ramp.

Twelve crates in three tiers. Tier 1 (mail-dane, mail-mta-sts, mail-dsn)
is standalone and publishable — no `dane` or `mta-sts` crate exists on
crates.io at all today.

openmail-relay ships the provider table as data, with SES and Oracle from
the start. Oracle's and Resend's SPF includes are deliberately None: a
guessed include turns the DNS check green against a mechanism the provider
does not honour, and mail still fails SPF silently.

cargo check/test/clippy/fmt all green; unsafe_code is forbidden workspace
wide; cargo-deny enforces the licence policy in CI.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JkyvfNJGTshJNE9FtwPLk7
2026-09-02 13:08:05 -07:00

1.3 KiB

Security policy

OpenMail runs a parser on port 25, exposed to the open internet, with its source published. That is the same position Postfix and Mox are in, and it is safe only with a real disclosure process. This is ours.

Reporting

Do not open a public issue for a security bug.

Use GitHub's private vulnerability reporting, or email the maintainer. We will acknowledge within 72 hours.

Scope — what we consider a vulnerability

  • Anything reachable pre-authentication on the SMTP listener.
  • MIME parsing that panics, hangs, or allocates unboundedly on crafted input.
  • A silent downgrade of a security property: DANE or MTA-STS reporting success where the policy was not actually satisfied, or a policy that should have been enforced being skipped. These are the highest-severity class in this codebase precisely because they do not look like failures.
  • Cross-tenant (pod) data access.
  • Authentication or scope bypass in the REST or MCP surfaces — especially an MCP tool reaching a credential route (see openmail_mcp::Exposure).

Not in scope

  • Deliverability problems (mail landing in spam).
  • Missing rate limits on an endpoint behind authentication, unless it is amplification.
  • Reports from automated scanners with no demonstrated impact.