How severe is CVE-2025-9791?

CVE-2025-9791 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-2025-9791 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-2025-9791?

CVE-2025-9791 affects Tenda Ac20 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-9791?

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-2025-9791 have an EU (EUVD) identifier?

Yes. CVE-2025-9791 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-26354.

When was CVE-2025-9791 published?

CVE-2025-9791 was published on 2025-09-01 and last updated on 2026-06-17.

CVE-2025-9791

CVE-2025-9791 is a high-severity vulnerability in Tenda Ac20 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-787.

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-2025-26354
Weakness: CWE-787
Affected product: Tenda Ac20 Firmware
Published: 2025-09-01
Last modified: 2026-06-17

Description

A weakness has been identified in Tenda AC20 16.03.08.05. This vulnerability affects unknown code of the file /goform/fromAdvSetMacMtuWan. This manipulation of the argument wanMTU causes stack-based buffer overflow. Remote exploitation of the attack is possible. The exploit has been made available to the public and could be exploited.

Frequently asked questions

What is CVE-2025-9791?: A weakness has been identified in Tenda AC20 16.03.08.05. This vulnerability affects unknown code of the file /goform/fromAdvSetMacMtuWan. This manipulation of the argument wanMTU causes stack-based buffer overflow. Remote exploitation of the attack is possible. The exploit has been made available to the public and could be exploited.
How severe is CVE-2025-9791?: CVE-2025-9791 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-2025-9791 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-2025-9791?: CVE-2025-9791 affects Tenda Ac20 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-9791?: 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-2025-9791 have an EU (EUVD) identifier?: Yes. CVE-2025-9791 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-26354.
When was CVE-2025-9791 published?: CVE-2025-9791 was published on 2025-09-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:tenda:ac20_firmware:16.03.08.5:*:*:*:*:*:*:*

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