MEDIUM · 6.5

CVE-2026-26312

Stalwart is a mail and collaboration server. A denial-of-service vulnerability exists in Stalwart Mail Server versions 0.13.0 through 0.15.4 where accessing a specially crafted email containing malfor...

Vulnerability Description

Stalwart is a mail and collaboration server. A denial-of-service vulnerability exists in Stalwart Mail Server versions 0.13.0 through 0.15.4 where accessing a specially crafted email containing malformed nested `message/rfc822` MIME parts via IMAP or JMAP causes excessive CPU and memory consumption, potentially leading to an out-of-memory condition and server crash. The malformed structure causes the `mail-parser` crate to produce cyclical references in its parsed representation, which Stalwart then follows indefinitely. Version 0.15.5 contains a patch.

CVSS Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH

Affected Products

VendorProductVersions
StalwStalwart>= 0.13.0, < 0.15.5

Related Weaknesses (CWE)

References

FAQ

What is CVE-2026-26312?

CVE-2026-26312 is a vulnerability with a CVSS score of 6.5 (MEDIUM). Stalwart is a mail and collaboration server. A denial-of-service vulnerability exists in Stalwart Mail Server versions 0.13.0 through 0.15.4 where accessing a specially crafted email containing malfor...

How severe is CVE-2026-26312?

CVE-2026-26312 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-26312?

Check the references section above for vendor advisories and patch information. Affected products include: Stalw Stalwart.