Unauthenticated mail relay via recipient validation mismatch
Published Aug 12, 2026 · Updated Aug 12, 2026
Email injection in Estatik Real Estate Plugin before 4.3.4 allows remote attackers to relay arbitrary messages to chosen recipients. The property request form verifies a signed configured-recipient value but later parses a different attacker-controlled recipient list for delivery. Exploitation requires a public request form configured for Other email; its nonce and signature can be replayed to set To, subject, body, and Reply-To fields.
Summary
What happened
Email injection in Estatik Real Estate Plugin before 4.3.4 allows remote attackers to relay arbitrary messages to chosen recipients. The property request form verifies a signed configured-recipient value but later parses a different attacker-controlled recipient list for delivery. Exploitation requires a public request form configured for Other email; its nonce and signature can be replayed to set To, subject, body, and Reply-To fields.
The record
- CVE
- CVE-2026-18044
- Published
- Aug 12, 2026
- Updated
- Aug 12, 2026
- Vendor
- Estatik Inc.
- Product
- Estatik Real Estate Plugin
- Classifications
- CWE-345, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 12, 2026CVE publishedPublication date reported by the CVE source.
- Aug 12, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <4.3.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- WPScan arbitrary-recipient mail relay proof of conceptfunctional · validated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo