CVE-2026-27856

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.39% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 32.2% of scored records. A rank, not a probability.

NVD base score

5.9 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

NVD analysis status

Modified. NVD last modified this record on 2026-07-15.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-03-27 08:10Z5 MO AGO

Last updated

2026-07-15 01:12Z1 MO AGO

Reserved

2026-02-24

Assigning CNA

OX

Record state

PUBLISHED

Severity

High (CVSS 7.4)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Weaknesses

• CWE-287Improper AuthenticationClass
• CWE-208Observable Timing DiscrepancyBase

Data version

5.2

Document digest

9f336920c77099eb5a3f1a228ca64777145fa6b2c1a609c443c657d9ac0c1926

• documentation.open-xchange.comhttps://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.jsonvendor-advisory
• access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-27856vdb-entryx_refsource_REDHAT
• bugzilla.redhat.comRHBZ#2452171https://bugzilla.redhat.com/show_bug.cgi?id=2452171issue-trackingx_refsource_REDHAT
• security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27856.jsonx_sadp-csaf-vex
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:26564vendor-advisoryx_refsource_REDHAT