CVE-2026-87886
HIGH 7.8 KNOWN EXPLOITEDLocal 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.
Confirmed exploited in the wild — in CISA KEV since 2026-09-16. Patch or mitigate now.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 14th percentile
Impact if exploited
7.8CVSS 3.0 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
Search for new PoCs
Search GitHub now — results may be empty or unverified.
Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Data snapshot:
Affected
Products Acronis Backup Plugin For Cpanel & Whm Acronis Backup Extension For Plesk Acronis Backup Plugin For Directadmin Acronis Backup Linux Kernel
Weakness (CWE)
- CWE-276: Incorrect default permissions
CVSS vector
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References and research data (JSON)
Additional exploitation reports
Source-specific reports, separate from CISA KEV. Repeated observations from one source are not independent confirmations.
- VulnCheck KEV · 2026-09-15T00:00:00Z
Source guidance: 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.
Source ransomware assessment: Unknown
VulnCheck KEV · CVE-2026-87886 · Updated 2026-09-15T00:00:00Z - VulnCheck KEV · 2026-09-15T00:00:00ZVulnCheck KEV · CVE-2026-87886
- VulnCheck KEV · 2026-09-16T00:00:00ZVulnCheck KEV · CVE-2026-87886
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Acronis | Acronis Backup | < 1.2.3 |
| Acronis | Acronis Backup | < 1.8.11 |
| Acronis | Acronis Backup | < 1.9.3 |
| Acronis | Acronis Backup | 1.9.3 |
| Acronis | Acronis Backup | 1.9.3 |
| Acronis | Acronis Backup | 1.9.3 |
All CVSS metrics
- HIGH 7.8 v3.0 · CNA Primary
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - HIGH 7.8 v3.0 · NVD Secondary
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Exploit-tagged references (not proof of a PoC)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-87886 CVE record · CISA-ADP · Updated 2026-09-18T14:33:42.532Z
NVD · CVE-2026-87886 · Updated 2026-09-18T19:29:35.067
Advisories
- https://security-advisory.acronis.com/advisories/SEC-10986 CVE record · Acronis · Updated 2026-09-17T23:09:27.166Z
NVD · CVE-2026-87886 · Updated 2026-09-18T19:29:35.067 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-82595 EUVD · EUVD-2026-82595
- https://vulncheck.com/kev VulnCheck KEV · CVE-2026-87886 · Updated 2026-09-15T00:00:00Z
Technical & other
- https://security-advisory.acronis.com/updates/UPD-2609-3d72-20a7 VulnCheck KEV · CVE-2026-87886 · Updated 2026-09-15T00:00:00Z
- https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json VulnCheck KEV · CVE-2026-87886 · Updated 2026-09-15T00:00:00Z