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Roundcube vs Stalwart

A side-by-side editorial comparison of Roundcube and Stalwart — release velocity, themes, recent moves, and the top alternatives to consider.

Roundcube vs Stalwart: at a glance

FeatureRoundcubeStalwart
SectorCommsComms
Velocity score5.06.3
Sparks · 30d01
Top themessecurity, xss, ssrf, email-securityemail-server, scim, jmap, enterprise-provisioning
Last editorial update8d ago8d ago
WebsiteVisit →Visit →

What is Roundcube?

Roundcube patches 28+ vulnerabilities across two branches in a five-month hardening sprint

Roundcube has shipped six security releases across its main 1.7.x and LTS 1.6.x branches since June, patching a cumulative 28+ vulnerabilities including an RCE via the markasjunk plugin's cmd_learn driver, IMAP command injection through LITERAL+ byte-count desynchronization, multiple SSRF bypasses, cross-user contact group access, and zero-click stored XSS. The simultaneous dual-branch cadence shows active maintenance of both lines.

Read the full Roundcube trajectory →

What is Stalwart?

Stalwart adds full SCIM v2 provisioning and 24-language calendar support as its standards coverage extends further than most commercial mail servers.

Stalwart is maintaining a weekly-or-faster release cadence, with alternating feature releases and dense bug-fix releases. The v0.16.20 release landed full SCIM v2 (Enterprise) including cursor-based pagination and the IPSIE lifecycle profile, conference links in calendar invites, and 24 new calendar interface translations. Below the feature line, the project is steadily closing correctness gaps across JMAP, CalDAV, IMAP, and MTA — many of them edge-case RFC compliance issues.

Read the full Stalwart trajectory →

Roundcube vs Stalwart: editorial side-by-side

R5.0

Roundcube patches 28+ vulnerabilities across two branches in a five-month hardening sprint

◆ Current state

Roundcube has shipped six security releases across its main 1.7.x and LTS 1.6.x branches since June, patching a cumulative 28+ vulnerabilities including an RCE via the markasjunk plugin's cmd_learn driver, IMAP command injection through LITERAL+ byte-count desynchronization, multiple SSRF bypasses, cross-user contact group access, and zero-click stored XSS. The simultaneous dual-branch cadence shows active maintenance of both lines.

◆ Where it's heading

The volume and variety of external security reports — from Horizon3.ai, Samsung R&D, pwn.ai, and independent researchers — indicates Roundcube's attack surface is under sustained scrutiny. The 1.7.0 release in May introduced meaningful features (Markdown rendering, improved OAuth2/OIDC, mandatory public_html entry point), but the months since have been consumed by patching. Feature development on 1.7.x appears paused until the security debt settles.

◆ Prediction

Another paired security release across 1.7.x and 1.6.x is likely within 6-8 weeks given the cadence. The SSRF and CSS parsing issues have required multiple iterations to close fully, suggesting the hardening work isn't finished.

S6.3

Stalwart adds full SCIM v2 provisioning and 24-language calendar support as its standards coverage extends further than most commercial mail servers.

◆ Current state

Stalwart is maintaining a weekly-or-faster release cadence, with alternating feature releases and dense bug-fix releases. The v0.16.20 release landed full SCIM v2 (Enterprise) including cursor-based pagination and the IPSIE lifecycle profile, conference links in calendar invites, and 24 new calendar interface translations. Below the feature line, the project is steadily closing correctness gaps across JMAP, CalDAV, IMAP, and MTA — many of them edge-case RFC compliance issues.

◆ Where it's heading

Stalwart is building toward parity with commercial enterprise mail servers on identity federation and provisioning (SCIM v2, VAPID for web push, DMARCbis/DKIM2 already landed). The pace of RFC implementation is unusually aggressive for an open-source project; the combination of JMAP, CalDAV, IMAP UIDONLY/UIDBATCHES, and SCIM v2 positions it as a viable self-hosted alternative for organizations that need standards compliance without vendor lock-in.

◆ Prediction

WebAuthn/passkey-based authentication and improved multi-tenant administration tooling are the most likely next capability additions, given the current trajectory toward enterprise identity management.

Alternatives to Roundcube and Stalwart

Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Roundcube or Stalwart.

See all Roundcube alternatives → · See all Stalwart alternatives →

Recent activity from Roundcube and Stalwart

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 10d agoStalwartv0.16.21
  2. 10d agoRoundcubeRoundcube Webmail 1.7.4
  3. 10d agoRoundcubeRoundcube Webmail 1.6.19
  4. 17d agoStalwartv0.16.20
  5. 22d agoStalwartv0.16.19
  6. 29d agoStalwartv0.16.18
  7. 1mo agoStalwartv0.16.17
  8. 1mo agoRoundcubeRoundcube Webmail 1.7.3
  9. 1mo agoRoundcubeRoundcube Webmail 1.6.18
  10. 1mo agoStalwartv0.16.16
  11. 2mo agoRoundcubeRoundcube Webmail 1.6.17
  12. 2mo agoRoundcubeRoundcube Webmail 1.7.2

Frequently asked questions

What is the difference between Roundcube and Stalwart?

They serve adjacent needs but don't currently overlap on shipped themes. Stalwart is currently shipping more aggressively (velocity 6.3 vs 5.0), with 1 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is Roundcube better than Stalwart?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Stalwart is currently shipping more aggressively (velocity 6.3 vs 5.0), with 1 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.

What are the best alternatives to Roundcube?

Top Roundcube alternatives in Comms are ranked by recent ship velocity. Browse the "Roundcube alternatives" section above for the current picks, or visit /alternatives/roundcube for the full list with editorial commentary on each.

What are the best alternatives to Stalwart?

Top Stalwart alternatives in Comms are ranked by recent ship velocity. Browse the "Stalwart alternatives" section above for the current picks, or visit /alternatives/stalwart for the full list with editorial commentary on each.