CVE-2026-87886

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.

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

Affected product

Acronis Backup

NVD also lists CPE entries for: Acronis Backup, Linux Kernel

References

• https://security-advisory.acronis.com/advisories/SEC-10986
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-87886
• https://nvd.nist.gov/vuln/detail/CVE-2026-87886
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Referenced in our briefings & reports

• Azure AI, Cisco ISE, WordPress flaws under active exploitation; 23M Gyazo breach (2026-09-19)

Related vulnerabilities

• CVE-2026-102489 – Zammad GmbH Zammad (same product)
• CVE-2026-102490 – Zammad GmbH Zammad (same product)
• CVE-2026-48449 – Adobe Campaign (same product)
• CVE-2026-53359 – Linux Kernel (same product)
• CVE-2026-53362 – Linux Kernel (same product)
• CVE-2026-53266 – Linux Kernel (same product)

Linux: 32 known exploited vulnerabilities (CISA KEV) →