Exploited vulnerability · CISA KEV

Is CVE-2026-87886 exploited? Yes: in CISA KEV since 16 Sep 2026

Gociux · Acronis Backup · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2026-87886, Acronis Backup Incorrect Default Permissions Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 16 Sep 2026. It affects Acronis Backup. If you run it, CISA's required action is: 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.

What it is

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

What to do

1. Check whether you run it. Look for Backup in your asset inventory, including appliances and cloud images. Stack check lists every exploited Acronis CVE at once.
2. Apply the fix. 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.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 17 Sep 2026.
4. Get told next time. Email alerts when CISA adds a CVE for Acronis.

References

• security-advisory.acronis.com/advisories/SEC-10986
• nvd.nist.gov/vuln/detail/CVE-2026-87886

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in September 2026 · Acronis scorecard · act-now radar.