---
title: "CVE-2026-87886: Acronis Backup Incorrect Default Permissions Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-87886/
description: "CVE-2026-87886 (Acronis Backup): Exploited in the wild (CISA KEV). Local privilege escalation due to insecure file permissions. The following products are…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-17
date_modified: 2026-09-18
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-87886"
kev: true
cvss: 7.8
epss: 0.00233
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-87886: Acronis Backup Incorrect Default Permissions Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Acronis Backup. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-09-16, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-09-19 ; treat that as the outer limit, not the target.
- EPSS 0.2% , percentile 13: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 13% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.
- Editorial verdict: Check exposure. Acronis Backup cPanel Plugin CVE-2026-87886: Exploited LPE — Only hosting servers running the Acronis Backup plugin for cPanel & WHM, Plesk or DirectAdmin are affected; on those, especially multi-tenant cPanel boxes, update the plugin now because it is being exploited.

## What it is

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.

## Affected products (CVE record)

- Acronis Acronis Backup plugin for cPanel & WHM: unspecified < 1.9.3.1021
- Acronis Acronis Backup extension for Plesk: unspecified < 1.8.11.638
- Acronis Acronis Backup plugin for DirectAdmin: unspecified < 1.2.3.238

## Severity

- Acronis CVSS 3.0: 7.8 `CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2026-09-16; federal due date 2026-09-19. Known ransomware use: Unknown.
- CISA 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 SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.23% probability of exploitation activity in the next 30 days; percentile 13.

## Sources

- [SEC-10986](https://security-advisory.acronis.com/advisories/SEC-10986)
- [CVE.org record CVE-2026-87886](https://www.cve.org/CVERecord?id=CVE-2026-87886)
- [NVD entry CVE-2026-87886](https://nvd.nist.gov/vuln/detail/CVE-2026-87886)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-87886)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk)

---
Source page: https://erroneo.us/security/cve/CVE-2026-87886/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt