Actively exploited · Published Sep 17, 2026 · Assigned by Acronis
CVE-2026-87886
High 7.8 Exploited
In plain English
A high-severity incorrect default permissions in Acronis Backup extension for Plesk from Acronis. Attackers are actively exploiting it in the wild (listed by CISA on September 16, 2026). The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA guidance
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Federal agencies must remediate by Sep 19, 2026.
Official description
Local privilege escalation due to insecure file permissions. The following products are affected: Acronis Backup plugin for cPanel & WHM (Linux) before build 1.9.3.1021, Acronis Backup extension for Plesk (Linux) before build 1.8.11.638, Acronis Backup plugin for DirectAdmin (Linux) before build 1.2.3.238.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Acronis | Acronis Backup plugin for cPanel & WHM | unspecified – before 1.9.3.1021 |
| Acronis | Acronis Backup extension for Plesk | unspecified – before 1.8.11.638 |
| Acronis | Acronis Backup plugin for DirectAdmin | unspecified – before 1.2.3.238 |
Weakness: CWE-276 · Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
- SEC-10986 vendor-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-87886 exploit