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Fencer Vulns
critical 9.8

CVE-2025-7673 json

A buffer overflow vulnerability in the URL parser of the zhttpd web server in Zyxel VMG8825-T50K firmware versions prior to V5.50(ABOM.5)C0…

published 2025-07-16 15 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-21579

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

A buffer overflow vulnerability in the URL parser of the zhttpd web server in Zyxel VMG8825-T50K firmware versions prior to V5.50(ABOM.5)C0 could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and potentially execute arbitrary code by sending a specially crafted HTTP request.

Patch / fix

  • zyxel emg3525-t50b_firmware 5.50\(abpm.4\)c0, 5.50\(absl.0\)b8
  • zyxel emg5523-t50b_firmware 5.50\(abpm.4\)c0, 5.50\(absl.0\)b8
  • zyxel emg5723-t50k_firmware 5.50\(abom.5\)c0
  • zyxel emg6726-b10a_firmware 5.13\(abnp.6\).c
  • zyxel ex3510-b0_firmware 5.17\(abup.3\)c0
  • zyxel ex5510-b0_firmware 5.15\(abqx.3\)c0
  • zyxel vmg1312-t20b_firmware 5.50\(absb.3\)c0
  • zyxel vmg3625-t50b_firmware 5.50\(abpm.4\)c0
  • zyxel vmg3925-b10b_firmware 5.13\(aavf.16\)c
  • zyxel vmg3925-b10c_firmware 5.13\(aavf.16\)c
  • zyxel vmg3927-b50a_firmware 5.15\(abmt.5\)c0
  • zyxel vmg3927-b60a_firmware 5.15\(abmt.5\)c0
  • zyxel vmg3927-b50b_firmware 5.13\(ably.6\)c0
  • zyxel vmg3927-t50k_firmware 5.50\(abom.5\)c0
  • zyxel vmg4005-b50b_firmware 5.13\(abrl.5\)c0
  • zyxel vmg4927-b50a_firmware 5.13\(ably.6\)c0
  • zyxel vmg8623-t50b_firmware 5.50\(abpm.4\)c0
  • zyxel vmg8825-b50a_firmware 5.15\(abmt.5\)c0
  • zyxel vmg8825-b60a_firmware 5.15\(abmt.5\)c0
  • zyxel vmg8825-bx0b_firmware 5.17\(abny.5\)c0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
15 mo ago

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Zyxel VMG8825-T50K firmware

Classification

Weakness
  • CWE-120 Buffer Copy without Checking Size of Input

References

Sources

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.