Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability

Zyxel GS1900 Series Switches

Zyxel GS1900 series switches contain a stack-based buffer overflow vulnerability in the CGI program which could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request. Added to CISA KEV on 2026-09-21 (federal deadline 2026-09-24).

First seen: 21 Sept 2026
Last update: 21 Sept 2026, 12:00 UTC
Identifiers: CVE-2026-7273
Source: CISA KEV

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability
Severity: high, exploited in the wild. Patch status: patched.
Affected: Zyxel GS1900 Series Switches
Ids: CVE-2026-7273

Zyxel GS1900 series switches contain a stack-based buffer overflow vulnerability in the CGI program which could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request. Added to CISA KEV on 2026-09-21 (federal deadline 2026-09-24).

## Steps
1. Search the repo, its CI and infra config for Zyxel GS1900 Series Switches. If present, report the version in use and whether it's affected.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-7273") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://nvd.nist.gov/vuln/detail/CVE-2026-7273 https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-stack-based-buffer-overflow-vulnerability-in-gs1900-series-switches-06-16-2026
https://pwned.coffee/i/zyxel-gs1900-series-switches-stack-based-buffer-overflow-cve-2026-7273

Sources

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