CVE-2022-26531

HIGH
7.8
CVSS Score
Published: May 24, 2022 at 12:00 AM UTC
Updated: June 17, 2026 at 04:35 AM UTC
136 products affected across 1 vendorUsg Flex 100W FirmwareUSG FLEX 200 firmwareUSG FLEX 700 firmware

Using USG/ZyWALL series firmware by Zyxel?

Get instant alerts when new vulnerabilities affect USG/ZyWALL series firmware - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.8
Exploit prediction
EPSS 6%

Description

Multiple improper input validation flaws were identified in some CLI commands of Zyxel USG/ZyWALL series firmware versions 4.09 through 4.71, USG FLEX series firmware versions 4.50 through 5.21, ATP series firmware versions 4.32 through 5.21, VPN series firmware versions 4.30 through 5.21, NSG series firmware versions 1.00 through 1.33 Patch 4, NXC2500 firmware version 6.10(AAIG.3) and earlier versions, NAP203 firmware version 6.25(ABFA.7) and earlier versions, NWA50AX firmware version 6.25(ABYW.5) and earlier versions, WAC500 firmware version 6.30(ABVS.2) and earlier versions, and WAX510D firmware version 6.30(ABTF.2) and earlier versions, that could allow a local authenticated attacker to cause a buffer overflow or a system crash via a crafted payload.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.32 ≤ v ≤ 5.21
4.32 ≤ v ≤ 5.21
zyxel-atp100w (same device)
4.32 ≤ v ≤ 5.21
zyxel-atp200 (same device)
4.32 ≤ v ≤ 5.21
zyxel-atp500 (same device)
4.32 ≤ v ≤ 5.21
zyxel-atp700 (same device)
4.32 ≤ v ≤ 5.21
zyxel-atp800 (same device)
v ≤ 6.25v ≤ 6.25(abfa.7)
zyxel-nap203 (same device)
v ≤ 6.25(abex.7)
zyxel-nap303 (same device)
v ≤ 6.25(abey.7)
zyxel-nap353 (same device)
Affected range stops below 1.33, so it looks safe — our inference, not a vendor statement
zyxel-nsg100 (same device)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-20

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card