How severe is CVE-2026-34121?

CVE-2026-34121 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-34121 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34121?

CVE-2026-34121 affects Tp-link Tapo C520ws Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34121?

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-2026-34121 have an EU (EUVD) identifier?

Yes. CVE-2026-34121 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18432.

When was CVE-2026-34121 published?

CVE-2026-34121 was published on 2026-04-02 and last updated on 2026-06-17.

CVE-2026-34121

CVE-2026-34121 is a high-severity vulnerability in Tp-link Tapo C520ws 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-287.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v4: 8.7
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18432
Weakness: CWE-287
Affected product: Tp-link Tapo C520ws Firmware
Published: 2026-04-02
Last modified: 2026-06-17

Description

An authentication bypass vulnerability within the HTTP handling of the DS configuration service in TP-Link Tapo C520WS v2.6 was identified, due to inconsistent parsing and authorization logic in JSON requests during authentication check. An unauthenticated attacker can append an authentication-exempt action to a request containing privileged DS do actions, bypassing authorization checks. Successful exploitation allows unauthenticated execution of restricted configuration actions, which may result in unauthorized modification of device state.

Frequently asked questions

What is CVE-2026-34121?: An authentication bypass vulnerability within the HTTP handling of the DS configuration service in TP-Link Tapo C520WS v2.6 was identified, due to inconsistent parsing and authorization logic in JSON requests during authentication check. An unauthenticated attacker can append an authentication-exempt action to a request containing privileged DS do actions, bypassing authorization checks. Successful exploitation allows unauthenticated execution of restricted configuration actions, which may result in unauthorized modification of device state.
How severe is CVE-2026-34121?: CVE-2026-34121 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-34121 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34121?: CVE-2026-34121 affects Tp-link Tapo C520ws Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34121?: 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-2026-34121 have an EU (EUVD) identifier?: Yes. CVE-2026-34121 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18432.
When was CVE-2026-34121 published?: CVE-2026-34121 was published on 2026-04-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:tp-link:tapo_c520ws_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Tp-link Tapo C520ws Firmware

CVE-2026-1315 — High (CVSS 7.5): By sending crafted files to the firmware update endpoint of Tapo C220 v1 and C520WS v2, the device terminates core…
CVE-2026-0919 — High (CVSS 7.5): The HTTP parser of Tapo C210 v3, C220 v1 and C520WS v2 cameras improperly handles requests containing an excessively…
CVE-2026-0918 — High (CVSS 7.5): The Tapo C100 v5, C220 v1 and C520WS v2 cameras’ HTTP service does not safely handle POST requests containing an…
CVE-2026-8714 — Medium (CVSS 6.5): A denial-of-service vulnerability exists in the RTSP server component of TP-Link Tapo C520WS v2 due to improper…
CVE-2026-34124 — Medium (CVSS 6.5): A denial-of-service vulnerability was identified in TP-Link Tapo C520WS v2.6 within the HTTP request path parsing…
CVE-2026-34122 — Medium (CVSS 6.5): A stack-based buffer overflow vulnerability was identified in TP-Link Tapo C520WS v2.6 within a configuration handling…

All CVEs affecting Tp-link Tapo C520ws Firmware →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

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