CVE-2026-87886
Acronis Backup Incorrect Default Permissions Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 19 September 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.0
- 7.8 HIGHCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.25% probability · 17th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 16 September 2026 · due 19 September 2026
- Weakness
- CWE-276
- Affected
- acronis/acronis backup
- Source
- security@acronis.com
EPSS 0.3% since 19 September 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
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. 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
References
- https://security-advisory.acronis.com/advisories/SEC-10986Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-87886US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.