How severe is CVE-2025-13943?

CVE-2025-13943 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-13943 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-13943?

CVE-2025-13943 primarily affects Zyxel Ex5601-t1 Firmware. In total, 52 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-13943?

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-2025-13943 have an EU (EUVD) identifier?

Yes. CVE-2025-13943 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-207550.

When was CVE-2025-13943 published?

CVE-2025-13943 was published on 2026-02-24 and last updated on 2026-06-17.

CVE-2025-13943

CVE-2025-13943 is a high-severity vulnerability in Zyxel Ex5601-t1 Firmware with a CVSS 3.x base score of 8.8. 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 8.8)
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-207550
Weakness: CWE-78
Affected product: Zyxel Ex5601-t1 Firmware
Published: 2026-02-24
Last modified: 2026-06-17

Description

A post-authentication command injection vulnerability in the log file download function of the Zyxel EX3301-T0 firmware versions through 5.50(ABVY.7)C0 could allow an authenticated attacker to execute operating system (OS) commands on an affected device.

Frequently asked questions

What is CVE-2025-13943?: A post-authentication command injection vulnerability in the log file download function of the Zyxel EX3301-T0 firmware versions through 5.50(ABVY.7)C0 could allow an authenticated attacker to execute operating system (OS) commands on an affected device.
How severe is CVE-2025-13943?: CVE-2025-13943 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-13943 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-13943?: CVE-2025-13943 primarily affects Zyxel Ex5601-t1 Firmware. In total, 52 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-13943?: 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-2025-13943 have an EU (EUVD) identifier?: Yes. CVE-2025-13943 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-207550.
When was CVE-2025-13943 published?: CVE-2025-13943 was published on 2026-02-24 and last updated on 2026-06-17.

References

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-null-pointer-dereference-and-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-security-routers-and-wireless-extenders-02-24-2026

Affected products (52)

cpe:2.3:o:zyxel:ex5601-t1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex7501-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex7710-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:gm4100-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:pm7500-00_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:vmg3625-t50b_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:vmg4005-b50a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:vmg4005-b60a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ax7501-b1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:pe3301-00_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:pe5301-01_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:pm3100-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:pm5100-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:pm5100-t1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:pm7300-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:px3321-t1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:px5301-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:vmg8623-t50b_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:we3300-00_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:wx3100-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:wx3401-b1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:wx5600-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:wx5610-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:dm4200-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:we4600-00_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:emg6726-b10a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:am7510-00_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:vmg4927-b50a_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5601-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5512-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5510-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex5401-b1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3600-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3510-b1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3510-b0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3501-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3500-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3301-t0_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3300-t1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:ex3300-t0_firmware:*:*:*:*:*:*:*:*

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