How severe is CVE-2025-40634?

CVE-2025-40634 has a CVSS 4.0 base score of 9.2, rated critical severity.

Is CVE-2025-40634 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-40634?

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

Does CVE-2025-40634 have an EU (EUVD) identifier?

Yes. CVE-2025-40634 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-15816.

When was CVE-2025-40634 published?

CVE-2025-40634 was published on 2025-05-20 and last updated on 2026-06-17.

CVE-2025-40634

CVE-2025-40634 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.2. 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-121.

Key facts

Severity: Critical (CVSS 4.0 base score 9.2)
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-15816
Weakness: CWE-121
Published: 2025-05-20
Last modified: 2026-06-17

Description

Stack-based buffer overflow vulnerability in the 'conn-indicator' binary running as root on the TP-Link Archer AX50 router, in firmware versions prior to 1.0.15 build 241203 rel61480. This vulnerability allows an attacker to execute arbitrary code on the device over LAN and WAN networks.

Frequently asked questions

What is CVE-2025-40634?: Stack-based buffer overflow vulnerability in the 'conn-indicator' binary running as root on the TP-Link Archer AX50 router, in firmware versions prior to 1.0.15 build 241203 rel61480. This vulnerability allows an attacker to execute arbitrary code on the device over LAN and WAN networks.
How severe is CVE-2025-40634?: CVE-2025-40634 has a CVSS 4.0 base score of 9.2, rated critical severity.
Is CVE-2025-40634 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-40634?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-40634 have an EU (EUVD) identifier?: Yes. CVE-2025-40634 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-15816.
When was CVE-2025-40634 published?: CVE-2025-40634 was published on 2025-05-20 and last updated on 2026-06-17.

References

https://www.incibe.es/en/incibe-cert/notices/aviso/stack-based-buffer-overflow-tp-link-archer-ax50

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