CVE-2026-26312
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…
Does this matter?
Lower severity and a low EPSS score (0.35%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.35% probability · 29th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- stalw/stalwart
- Source
- security-advisories@github.com
References
- https://github.com/stalwartlabs/stalwart/security/advisories/GHSA-jm95-876q-c9gwExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.