Not scored yet

CVE-2026-12339

A Zip Slip vulnerability in the WebUI ISP Upgrade functionality allows arbitrary file write via a crafted archive containing directory traversal sequences. An authenticated administrator may overwrite arbitrary files on the system.Successful exploitation may allow arbitrary file to be overwritten on the underlying system, affecting system integrity and availability.

What this means for your business

  • FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 27% of all known flaws.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
Not yet scored
CVSS v4
6.9
Weakness
CWE-22
Assigned by
f23511db-6c3e-4e32-a477-6aa17d310630

Dates

Published
2026-08-10
Last modified
2026-08-26
Sources
NVD

References