CVE-2026-87886

Acronis Backup privilege escalation, confirmed exploited in the wild.

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

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0.2%chance of exploitation in the next 30 days (EPSS), 14th percentile

16 Sepadded to CISA's Known Exploited Vulnerabilities list, 2026

19 Sepfederal remediation deadline, already passed

Passedpast the deadline: patch now

CISA's name for it	Acronis Backup Incorrect Default Permissions Vulnerability
Vendor and product	Acronis · Backup
Type	privilege escalation · CWE-276
Exploited	Confirmed by CISA listed 16 September 2026
Likelihood	scored lower by EPSS, but already confirmed exploited, which outranks any prediction
Deadline	19 September 2026 · already passed
Used in ransomware	Not reported
Advisories	security-advisory.acronis.com ↗ · www.cisa.gov ↗ · www.cisa.gov ↗ · nvd.nist.gov ↗

What to do

Three steps, in this order

Step 1

Install the update on every affected system, servers and workstations alike.

Step 2

Escalation bugs are chained after a first foothold: check for other exposures an attacker could start from.

Step 3

Review who holds administrative rights, and alert on new ones.

CISA's 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.

CISA's 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.

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Questions

CVE-2026-87886 in short

Is CVE-2026-87886 being exploited?

Yes. CISA added CVE-2026-87886 to its Known Exploited Vulnerabilities catalogue on 16 September 2026, which it does only on evidence of exploitation in the wild.

What is the CISA deadline for CVE-2026-87886?

US federal agencies must remediate it by 19 September 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.

How likely is CVE-2026-87886 to be exploited in the next 30 days?

FIRST's Exploit Prediction Scoring System gives it 0.2%, the 14th percentile of every CVE it scores.

How do I fix CVE-2026-87886?

Install the update on every affected system, servers and workstations alike. Escalation bugs are chained after a first foothold: check for other exposures an attacker could start from. Review who holds administrative rights, and alert on new ones.

Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.