High7.4Red Hat Linux

High [CVE-2026-27856] Full access via timing oracle attack in credential verification

This high-severity Red Hat Linux advisory covers CVE-2026-27856 affecting Red Hat Enterprise Linux 7 Extended Lifecycle Support, Red Hat Enterprise Linux 6.

CVE-2026-27856 Published Mar 27, 2026

CVE-2026-27856

Affected products & platforms

Red Hat LinuxUnclassified

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Summary

Full access via timing oracle attack in credential verification. Red Hat rates this important (CVSS 7.4).

Weakness: CWE-208. Affected package(s): dovecot.

Resolved in Red Hat advisory RHSA-2026:26564 — update the affected packages (`sudo dnf update`).

Affected products named by the advisory: Red Hat Enterprise Linux 7 Extended Lifecycle Support; Red Hat Enterprise Linux 6.

Affected versions

dovecot-1:2.2.36-8.el7_9.1

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Fixed versions

RHSA-2026:26564

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Mitigation checklist

Recommended fix / mitigation

Update the affected package(s) to the fixed version shipped in RHSA-2026:26564 (`sudo dnf update` / `yum update`).

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

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