VulnerabilityModified

CVE-2026-24031

Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin.

HIGH 8.2EPSS 0.40%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. This vulnerability allows bypassing authentication for any user and user enumeration. Do not clear auth_username_chars. If this is not possible, install latest fixed version. No publicly available exploits are known.

CVSS 3.1: 8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
EPSS: 0.40% probability · 33th percentile
CISA KEV: Not listed
Weakness: CWE-89
Affected: dovecot/dovecot · open-xchange/dovecot
Source: security@open-xchange.com

References

https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.jsonVendor Advisory
https://access.redhat.com/security/cve/CVE-2026-24031
https://bugzilla.redhat.com/show_bug.cgi?id=2452181
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-24031.json

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.