What is CVE-2026-26312?

CVE-2026-26312 is a medium-severity vulnerability in Stalw Stalwart, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 6.5/10. Published 2026-02-19.

How severe is CVE-2026-26312?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Resource exhaustion in Stalw Stalwart

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…

EPSS: 0.004 (27.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Stalw Stalwart
Stalwartlabs Stalwart — versions >= 0.13.0, < 0.15.5

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-26312?: CVE-2026-26312 is a medium-severity vulnerability in Stalw Stalwart, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 6.5/10. Published 2026-02-19.
How severe is CVE-2026-26312?: Medium severity. CVSS v3 base score is 6.5 out of 10.