How severe is CVE-2026-36778?

CVE-2026-36778 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-36778 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-36778?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-36778 have an EU (EUVD) identifier?

Yes. CVE-2026-36778 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35936.

When was CVE-2026-36778 published?

CVE-2026-36778 was published on 2026-06-09 and last updated on 2026-06-17.

CVE-2026-36778

CVE-2026-36778 is a medium-severity vulnerability with a CVSS 3.x base score of 4.9. 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 3.x base score 4.9)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-35936
Weakness: CWE-121
Published: 2026-06-09
Last modified: 2026-06-17

Description

Shenzhen Tenda Technology Co., Ltd Tenda O3 Wireless Router v1.0.0.5(4180) was discovered to contain a stack overflow in the username parameter of the R7WebsSecurityHandler function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted HTTP request.

Frequently asked questions

What is CVE-2026-36778?: Shenzhen Tenda Technology Co., Ltd Tenda O3 Wireless Router v1.0.0.5(4180) was discovered to contain a stack overflow in the username parameter of the R7WebsSecurityHandler function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted HTTP request.
How severe is CVE-2026-36778?: CVE-2026-36778 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-36778 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-36778?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-36778 have an EU (EUVD) identifier?: Yes. CVE-2026-36778 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35936.
When was CVE-2026-36778 published?: CVE-2026-36778 was published on 2026-06-09 and last updated on 2026-06-17.

References

https://github.com/xhh0124/SemVulLLM/tree/main/O3/R7WebsSecurityHandler

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