CVE-2026-42008

MEDIUM
4.3
CVSS Score
Published: August 28, 2026 at 10:12 AM UTC
Updated: September 3, 2026 at 06:24 PM UTC
1 product affected across 1 vendorOX Dovecot

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.3.4 ≤ v < 2.3.22.22.3.4 ≤ v < 2.4.53.0.0 ≤ v < 3.0.73.1.0 ≤ v < 3.1.62.3.43.0.03.1.0
Affected range stops below 2.3.22.2, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.4.5, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.0.7, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.1.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMOX
Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-287

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