CVE-2022-26531 json
Multiple improper input validation flaws were identified in some CLI commands of Zyxel USG/ZyWALL series firmware versions 4.09 through 4.7…
published 2022-05-24 4 y ago modified 2026-06-17 4 mo ago also EUVD-2022-31088
- cvss
- 6.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 6.4%
- EPSS 6.4% chance of exploitation in 30 days, percentile 93%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- zyxel nsg300_firmware 1.33
- zyxel nsg100_firmware 1.33
- zyxel nsg50_firmware 1.33
Exploit prediction
6.37% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H |
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 4.6 | AV:L/AC:L/Au:N/C:P/I:P/A:P |
Affected products
- Zyxel USG/ZyWALL series firmware
- Zyxel USG FLEX series firmware
- Zyxel ATP series firmware
- Zyxel VPN series firmware
- Zyxel NSG series firmware
- Zyxel NXC2500 firmware
- Zyxel NAP203 firmware
- Zyxel NWA50AX firmware
- Zyxel WAC500 firmware
- Zyxel WAX510D firmware
Classification
- Weakness
-
- CWE-20 Improper Input Validation
References
-
zyxel.com
/support/multiple-vulnerabilities-of-firewalls-AP-controllers-and-APs.shtml
vendor-advisory
-
seclists.org
/fulldisclosure/2022/Jun/15
mailing-list
- packetstormsecurity.com /files/167464/Zyxel-Buffer-Overflow-Format-String-Command-Injection.html
- packetstormsecurity.com /files/177036/Zyxel-zysh-Format-String-Proof-Of-Concept.html
Sources
- CVE List CVE-2022-26531
- NVD CVE-2022-26531
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.