CVE-2026-6239
CVE-2026-6239 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.8. 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-121.
Key facts
- Severity: Medium (CVSS 4.0 base score 6.8)
- EPSS exploit prediction: 0% (8th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-34934
- Weakness: CWE-121
- Published:
- Last modified:
Description
A stack‑based buffer overflow vulnerability exists in Tapo C520WS v2 in the ONVIF CreateUsers service, where the device fails to properly validate the number of XML user nodes during request processing. An authenticated attacker can send a specially crafted ONVIF request containing an excessive number of user entries to trigger memory corruption. Successful exploitation may cause the ONVIF management service to terminate unexpectedly, resulting in a denial‑of‑service (DoS) condition that disrupts device configuration and management functions.
Frequently asked questions
- What is CVE-2026-6239?
- A stack‑based buffer overflow vulnerability exists in Tapo C520WS v2 in the ONVIF CreateUsers service, where the device fails to properly validate the number of XML user nodes during request processing. An authenticated attacker can send a specially crafted ONVIF request containing an excessive number of user entries to trigger memory corruption. Successful exploitation may cause the ONVIF management service to terminate unexpectedly, resulting in a denial‑of‑service (DoS) condition that disrupts device configuration and management functions.
- How severe is CVE-2026-6239?
- CVE-2026-6239 has a CVSS 4.0 base score of 6.8, rated medium severity.
- Is CVE-2026-6239 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-6239?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-6239 have an EU (EUVD) identifier?
- Yes. CVE-2026-6239 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34934.
- When was CVE-2026-6239 published?
- CVE-2026-6239 was published on 2026-06-06 and last updated on 2026-06-17.
References
- https://www.tp-link.com/en/support/download/tapo-c520ws/#Firmware-Release-Notes
- https://www.tp-link.com/us/support/download/tapo-c520ws/#Firmware-Release-Notes
- https://www.tp-link.com/us/support/faq/5120/
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