How severe is CVE-2026-34866?

CVE-2026-34866 has a CVSS 3.x base score of 5.1, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2026-34866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34866?

CVE-2026-34866 affects Huawei Harmonyos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34866?

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

Does CVE-2026-34866 have an EU (EUVD) identifier?

Yes. CVE-2026-34866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21879.

When was CVE-2026-34866 published?

CVE-2026-34866 was published on 2026-04-13 and last updated on 2026-06-17.

CVE-2026-34866

CVE-2026-34866 is a medium-severity vulnerability in Huawei Harmonyos with a CVSS 3.x base score of 5.1. 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-120.

Key facts

Severity: Medium (CVSS 3.x base score 5.1)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21879
Weakness: CWE-120
Affected product: Huawei Harmonyos
Published: 2026-04-13
Last modified: 2026-06-17

Description

Out-of-bounds write vulnerability in the WEB module.Impact: Successful exploitation of this vulnerability will affect availability and confidentiality.

Frequently asked questions

What is CVE-2026-34866?: Out-of-bounds write vulnerability in the WEB module.Impact: Successful exploitation of this vulnerability will affect availability and confidentiality.
How severe is CVE-2026-34866?: CVE-2026-34866 has a CVSS 3.x base score of 5.1, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2026-34866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34866?: CVE-2026-34866 affects Huawei Harmonyos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34866?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34866 have an EU (EUVD) identifier?: Yes. CVE-2026-34866 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21879.
When was CVE-2026-34866 published?: CVE-2026-34866 was published on 2026-04-13 and last updated on 2026-06-17.

References

https://consumer.huawei.com/en/support/bulletinwearables/2026/4/

Affected products (1)

cpe:2.3:o:huawei:harmonyos:6.0.0:*:*:*:*:*:*:*

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