4.0Medium

CVE-2026-89045

zstd-jni versions 1.4.8-4 through 1.5.7-13 fail to validate negative length parameters in ZstdInputStreamNoFinalizer.read(), allowing attackers to trigger infinite loops. Attackers can pass negative length values to cause the read method to spin indefinitely while holding the stream monitor, blocking all other threads from accessing the stream.

What this means for your business

  • An attacker can use it only with access to the machine itself, without a login, and without anyone at your company clicking anything.

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
4.0 (v3.1)
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS v4
5.1
Weakness
CWE-835
Assigned by
disclosure@vulncheck.com

Dates

Published
2026-09-10
Last modified
2026-09-15
Sources
NVD

References