CVE-2026-87886: Acronis Backup

What is CVE-2026-87886?

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.

CVSS7.8 NVD 3.0

SeverityHIGH

Exploitation In the wild In CISA KEV

EPSS<1% · P21

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWECWE-276

NVD published2026-09-17

NVD last modified2026-09-18

Timeline

2026-09-16Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-09-17Published to the U.S. National Vulnerability Database (NVD)
2026-09-18NVD record last updated
2026-09-19First covered in a defend.network daily briefing
2026-09-19CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

Acronis Backup Incorrect Default Permissions Vulnerability

Added to KEV2026-09-16

Federal patch deadline2026-09-19

Known ransomware useUnknown

Affected product

Acronis Backup

Remediation Steps

Apply the vendor security update for Acronis Backup (cPanel & WHM, Plesk) as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 2 of September 2026 (September 14 – 20)
Azure AI, Cisco ISE, WordPress flaws under active exploitation; 23M Gyazo breach (2026-09-19)

Browse all tracked CVEs in the defend.network CVE database →

🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.