How severe is CVE-2025-8078?

CVE-2025-8078 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-8078 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-8078?

CVE-2025-8078 affects Zyxel Zld. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-8078?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-8078 have an EU (EUVD) identifier?

Yes. CVE-2025-8078 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-35120.

When was CVE-2025-8078 published?

CVE-2025-8078 was published on 2025-10-21 and last updated on 2026-06-17.

CVE-2025-8078

CVE-2025-8078 is a high-severity vulnerability in Zyxel Zld with a CVSS 3.x base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 7.2)
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-35120
Weakness: CWE-78
Affected product: Zyxel Zld
Published: 2025-10-21
Last modified: 2026-06-17

Description

A post-authentication command injection vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from V4.50 through V5.40, USG FLEX 50(W) series firmware versions from V4.16 through V5.40, and USG20(W)-VPN series firmware versions from V4.16 through V5.40 could allow an authenticated attacker with administrator privileges to execute operating system (OS) commands on the affected device by passing a crafted string as an argument to a CLI command.

Frequently asked questions

What is CVE-2025-8078?: A post-authentication command injection vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from V4.50 through V5.40, USG FLEX 50(W) series firmware versions from V4.16 through V5.40, and USG20(W)-VPN series firmware versions from V4.16 through V5.40 could allow an authenticated attacker with administrator privileges to execute operating system (OS) commands on the affected device by passing a crafted string as an argument to a CLI command.
How severe is CVE-2025-8078?: CVE-2025-8078 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-8078 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-8078?: CVE-2025-8078 affects Zyxel Zld. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-8078?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-8078 have an EU (EUVD) identifier?: Yes. CVE-2025-8078 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-35120.
When was CVE-2025-8078 published?: CVE-2025-8078 was published on 2025-10-21 and last updated on 2026-06-17.

References

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-post-authentication-command-injection-and-missing-authorization-vulnerabilities-in-zld-firewalls-10-21-2025

Affected products (1)

cpe:2.3:o:zyxel:zld:*:*:*:*:*:*:*:*

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