ZDI-26-424: Synology DiskStation DS925+ MailPlus Improper Restriction of Communication Channel to Intended Endpoints Vulnerability
This vulnerability allows network-adjacent attackers to access the Redis instance on affected installations of Synology DiskStation DS925+ devices. Authentication is not required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 4.3. The following CVEs are assigned: CVE-2026-13135.
AI Analysis
Technical Summary
CVE-2026-13135 is an improper restriction of communication channel vulnerability affecting Synology DiskStation DS925+ MailPlus. The vulnerability arises from the MailPlus firewall rules exposing the Redis instance over IPv6, allowing network-adjacent attackers to access Redis without authentication. Exploitation can lead to arbitrary code execution with root privileges when combined with other vulnerabilities. Synology has released an update to fix this issue.
Potential Impact
An attacker on the network adjacent to the affected device can access the Redis instance without authentication, potentially leading to arbitrary code execution as root when combined with other vulnerabilities. The confidentiality impact is limited (partial information disclosure), with no integrity or availability impact directly from this vulnerability alone.
Mitigation Recommendations
Synology has issued an official update to correct this vulnerability. Users should apply the update provided by Synology to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
ZDI-26-424: Synology DiskStation DS925+ MailPlus Improper Restriction of Communication Channel to Intended Endpoints Vulnerability
Description
This vulnerability allows network-adjacent attackers to access the Redis instance on affected installations of Synology DiskStation DS925+ devices. Authentication is not required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 4.3. The following CVEs are assigned: CVE-2026-13135.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-13135 is an improper restriction of communication channel vulnerability affecting Synology DiskStation DS925+ MailPlus. The vulnerability arises from the MailPlus firewall rules exposing the Redis instance over IPv6, allowing network-adjacent attackers to access Redis without authentication. Exploitation can lead to arbitrary code execution with root privileges when combined with other vulnerabilities. Synology has released an update to fix this issue.
Potential Impact
An attacker on the network adjacent to the affected device can access the Redis instance without authentication, potentially leading to arbitrary code execution as root when combined with other vulnerabilities. The confidentiality impact is limited (partial information disclosure), with no integrity or availability impact directly from this vulnerability alone.
Mitigation Recommendations
Synology has issued an official update to correct this vulnerability. Users should apply the update provided by Synology to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Article Source
- {"url":"http://www.zerodayinitiative.com/advisories/ZDI-26-424/","fetched":true,"fetchedAt":"2026-07-16T15:51:06.391Z","wordCount":193}
- Classification
- {"confidence":0.95,"severitySource":"cvss-text","classifier":"rss-v2"}
Threat ID: 6a58fe6768715ace43485c29
Added to database: 07/16/2026, 15:53:11 UTC
Last enriched: 08/07/2026, 06:03:58 UTC
Last updated: 08/28/2026, 22:25:04 UTC
Views: 71
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