Vulnerability Details 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 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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 12.0%
CVSS Severity
CVSS v3 Score 6.5
Products affected by CVE-2026-26312
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cpe:2.3:a:stalw:stalwart:0.13.0
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cpe:2.3:a:stalw:stalwart:0.13.1
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cpe:2.3:a:stalw:stalwart:0.13.2
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cpe:2.3:a:stalw:stalwart:0.13.3
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cpe:2.3:a:stalw:stalwart:0.13.4
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cpe:2.3:a:stalw:stalwart:0.14.0
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cpe:2.3:a:stalw:stalwart:0.14.1
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cpe:2.3:a:stalw:stalwart:0.15.0
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cpe:2.3:a:stalw:stalwart:0.15.1
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cpe:2.3:a:stalw:stalwart:0.15.2
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cpe:2.3:a:stalw:stalwart:0.15.3
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cpe:2.3:a:stalw:stalwart:0.15.4