CVE WatchSep 18, 2026

CVE-2026-87886

Acronis Backup Incorrect Default Permissions Vulnerability

CVSS

7.8

High

EPSS

0.2%

p14

KEV

YES

Sep 16, 2026

Exploit Today

0-100

Published: Sep 17, 2026 · Last modified: Sep 18, 2026 · CWE-276

EPSS · 30d

0.2%EPSS · 30 days0.2%

2026-10-032026-10-31

KEV catalog record

Product

Acronis / Backup

Vulnerability

Acronis Backup Incorrect Default Permissions Vulnerability

Added to KEV

Sep 16, 2026

Remediate by

Sep 19, 2026

Known ransomware use

Summary description

Acronis Backup plugin for cPanel & WHM and extension for Plesk contains an incorrect default permissions vulnerability that could allow for privilege escalation.

Required action

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.

Notes

https://security-advisory.acronis.com/advisories/SEC-10986 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-87886

Technical 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.

Official references

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