How severe is CVE-2025-7421?

CVE-2025-7421 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-2025-7421 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-7421?

CVE-2025-7421 affects Tenda O3 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-7421?

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-2025-7421 have an EU (EUVD) identifier?

Yes. CVE-2025-7421 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-21090.

When was CVE-2025-7421 published?

CVE-2025-7421 was published on 2025-07-11 and last updated on 2026-06-17.

CVE-2025-7421

CVE-2025-7421 is a high-severity vulnerability in Tenda O3 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-119.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
CVSS v4: 7.4
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-21090
Weakness: CWE-119
Affected product: Tenda O3 Firmware
Published: 2025-07-11
Last modified: 2026-06-17

Description

A vulnerability was found in Tenda O3V2 1.0.0.12(3880). It has been rated as critical. This issue affects the function fromMacFilterModify of the file /goform/operateMacFilter of the component httpd. The manipulation of the argument mac leads to stack-based buffer overflow. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used.

Frequently asked questions

What is CVE-2025-7421?: A vulnerability was found in Tenda O3V2 1.0.0.12(3880). It has been rated as critical. This issue affects the function fromMacFilterModify of the file /goform/operateMacFilter of the component httpd. The manipulation of the argument mac leads to stack-based buffer overflow. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used.
How severe is CVE-2025-7421?: CVE-2025-7421 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-2025-7421 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-7421?: CVE-2025-7421 affects Tenda O3 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-7421?: 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-2025-7421 have an EU (EUVD) identifier?: Yes. CVE-2025-7421 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-21090.
When was CVE-2025-7421 published?: CVE-2025-7421 was published on 2025-07-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:tenda:o3_firmware:1.0.0.12\(3880\):*:*:*:*:*:*:*

More vulnerabilities in Tenda O3 Firmware

CVE-2025-55613 — Critical (CVSS 9.8): Tenda O3V2 1.0.0.12(3880) is vulnerable to Buffer Overflow in the fromSafeSetMacFilter function via the mac parameter.
CVE-2024-36604 — Critical (CVSS 9.8): Tenda O3V2 v1.0.0.12(3880) was discovered to contain a Blind Command Injection via stpEn parameter in the SetStp…
CVE-2025-7423 — High (CVSS 8.8): A vulnerability classified as critical was found in Tenda O3V2 1.0.0.12(3880). Affected by this vulnerability is the…
CVE-2025-7422 — High (CVSS 8.8): A vulnerability classified as critical has been found in Tenda O3V2 1.0.0.12(3880). Affected is the function…
CVE-2025-7420 — High (CVSS 8.8): A vulnerability was found in Tenda O3V2 1.0.0.12(3880). It has been declared as critical. This vulnerability affects…
CVE-2025-7419 — High (CVSS 8.8): A vulnerability was found in Tenda O3V2 1.0.0.12(3880). It has been classified as critical. This affects the function…

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