CVE-2026-87886

CISA Known Exploited Vulnerability

Acronis Backup Incorrect Default Permissions Vulnerability — Acronis Backup

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

Added to KEV

2026-09-16

Remediation due

2026-09-19

Ransomware use

Unknown

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