Acronis Backup: attackers can gain admin rights
OFFICIAL NAME: Acronis Backup Incorrect Default Permissions Vulnerability
WHAT IT IS · SERVERS AND BACKUPSIt runs or protects many systems at once, including your backups.
DO THIS FIRSTPatch it and keep its admin access off the internet. Not sure if you use it? Send this page to your IT provider or security lead and ask.
TECHNICAL SUMMARY Acronis Backup plugin for cPanel & WHM and extension for Plesk contains an incorrect default permissions vulnerability that could allow for privilege escalation.
WHY THIS VERDICT Attacks are confirmed. The vulnerability is 54 days old, so many systems are likely still unpatched.
WHY IT RANKS HERE Exploitation is confirmed by an authoritative source. 4 products are affected.
- HIGHEST CONFIRMED RUNG
- EXPLOITED
- CISA KEV
- LISTED
- EXPLOIT CODE
- NONE KNOWN
How far has it climbed?
01 TALK
□ NO EVIDENCE YETNEWEST EVIDENCE NONE YETNo evidence yet.
SRC: NONE YET02 EXPOSED
□ NOT TRACKED YETNO SOURCE FOR THIS STEP YETWe have no source that counts exposed systems yet. Internet scan data needs a partnership we do not have. No evidence here does not mean nothing is exposed.
03 TRIED
■ CONFIRMEDNEWEST EVIDENCE · 2 INDEPENDENT SOURCESAttacks that worked are confirmed (step 4), so attempts count as confirmed too.
04 EXPLOITED
■ CONFIRMEDNEWEST EVIDENCE · 2 INDEPENDENT SOURCESCISA Vulnrichment marks CVE-2026-87886 as actively exploited. Acronis Backup plugin for cPanel & WHM and extension for Plesk contains an incorrect default permissions vulnerability that could allow for privilege escalation.
05 DAMAGE
□ NOT TRACKED YETNO SOURCE FOR THIS STEP YETBreach notices and filings rarely name the flaw that was used, so we cannot link them to this event yet. No evidence here does not mean no harm.
When each thing happened
- DISCLOSED
- EXPLOIT CODE PUBLICNOT YET
- FIRST ATTACK REPORT
- CISA KEV LISTING
- US FEDERAL DEADLINE
THE FIX
CISA's instruction: apply the vendor's fix, or stop using the product if no fix exists. The deadline CISA set for US federal agencies, Sep 19, 2026, has passed. It is a US government deadline; use it as a guide.
Questions to ask this week
- Do we run Acronis Backup? If yes, is it patched or cut off from the internet?
- Who owns fixing it, and by what date?
- Have we checked for signs of attack since the first report, not just since the patch?
How it unfolded
- Attack activity. SEP 15, 2026Acronis Backup Incorrect Default Permissions Vulnerability
- Attack activity. SEP 17, 2026CISA Vulnrichment marks CVE-2026-87886 as actively exploited