CISA orders feds to patch Zyxel flaw exploited for data theft
Source Bleeping Computer
Exploited in the wild · KEV due 24 Sep 2026 : apply the vendor's fix or mitigations to GS1900-48HPv2 firmware now.
Data as of 6 Nov 2026, 23:24 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 16 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 97 days after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Zyxel Corporation
, 49 days before disclosure
CVE published
on cve.org
, t = 0
In Threat Radar
record ingested
, 40 minutes after disclosure
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, 97 days after disclosure
KEV remediation due
US federal deadline
, 100 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ZyxelGS1900-48HPv2 firmware | Affected
| Fixed in– |
| ZyxelGS1900-8 firmware | Affected
| Fixed in– |
| ZyxelGS1900-8HP firmware | Affected
| Fixed in– |
| ZyxelGS1900-10HP firmware | Affected
| Fixed in– |
| ZyxelGS1900-16 firmware | Affected
| Fixed in– |
| ZyxelGS1900-24 firmware | Affected
| Fixed in– |
AI-suggested
Zyxel released official firmware updates on June 16, 2026, that address this vulnerability. Affected users should upgrade to the patched firmware versions immediately to ensure protection. Federal agencies are mandated by CISA's Binding Operational Directive 26-04 to patch affected devices promptly. Organizations are encouraged to prioritize remediation of this vulnerability as it is actively exploited in the wild. No alternative mitigations or workarounds are specified.
Description
A high-severity stack-based buffer overflow vulnerability (CVE-2026-7273) in Zyxel GS1900 series switches allows unauthenticated attackers on the local network to execute OS commands via crafted HTTP requests. This vulnerability is actively exploited in the wild for data theft. Zyxel released firmware updates to address the issue in June 2026. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has mandated federal agencies to patch affected devices promptly and added the vulnerability to its Known Exploited Vulnerabilities Catalog. Threat intelligence reports indicate nearly 1,000 devices were compromised globally, with data exfiltration confirmed. The affected devices are widely deployed by internet service providers worldwide.