Acronis Backup CVE-2026-87886 exploited in the wild
Executive summary
CISA lists CVE-2026-87886, a vulnerability in Acronis Backup, in the Known Exploited Vulnerabilities catalog (added 2026-09-16, due 2026-09-19), and NVD records a CVSS of 7.8. This report summarizes public CTI only.
Technical analysis
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. CPE: CWE-276. CVSS vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
IOCs
No public IOC is available.
CVEs and affected products
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.
ATT&CK mapping
Exploit Public-Facing Application
Tactic: Initial Access
Detection content
Sigma rules, YARA rules, Splunk SPL, and KQL detection logic.
Threat hunting
Hypothesis-driven hunt procedures and telemetry checklist.
Remediation
Containment actions, patching notes, and credential steps.
Historical relationships
No published historical relationship is available.
Timeline and change history
Confidence and caveats
0.9
⚠️ This report describes public CTI and does not assess any specific organization's exposure.
⚠️ Detection queries are templates and require local validation.
⚠️ Exploitation status reflects the public CISA KEV catalog record.
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Intelligence Sources & Advisory Feeds
DFIR investigations, vendor research, advisory feeds & verified claims
8 references
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Evidence consists of the NVD record, the CISA KEV catalog entry, the FIRST EPSS model output, and indexed source documents that reference this CVE.
NVD entry for 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. The record carries CVSS 7.8 (3.0) vector CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, weaknesses CWE-276.
CISA added CVE-2026-87886 to the Known Exploited Vulnerabilities catalog on 2026-09-16 with a required due date of 2026-09-19, recording the vulnerability as exploited in the wild and affecting vendor Acronis, product Backup. 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.
FIRST EPSS models an exploitation probability of 0.00233 (percentile 0.12616) for CVE-2026-87886.
Source nist-national-vulnerability-database-nvd published 2026-09-17 at https://nvd.nist.gov/vuln/detail/CVE-2026-87886 references CVE-2026-87886 affecting Acronis Backup.
Source soc-prime-detection-news published 2026-09-17 at https://socprime.com/blog/cve-2026-87886-acronis-backu-plugin-flaw-exploited/ references CVE-2026-87886 affecting Acronis Backup.
Source cisa-cybersecurity-advisories published 2026-09-16 at https://www.cisa.gov/news-events/alerts/2026/09/16/cisa-adds-two-known-exploited-vulnerabilities-catalog references CVE-2026-87886 affecting Acronis Backup.
Source the-hacker-news published 2026-09-16 at https://thehackernews.com/2026/09/acronis-cpanel-backup-plugin.html references CVE-2026-87886 affecting Acronis Backup.
Source cisa-known-exploited-vulnerabilities published 2026-09-16 at https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json#CVE-2026-87886 references CVE-2026-87886 affecting Acronis Backup.