CVE-2026-86250

h3 versions before 2.0.1-rc.18 fail to validate the chunk count parsed from user-controlled cookie values in setChunkedCookie() and deleteChunkedCookie() functions. Attackers can send a crafted cookie header with an extremely large chunk count to trigger an O(n²) cleanup loop that hangs the server process.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/h3js/h3/security/advisories/GHSA-q5pr-72pq-83v3
https://www.vulncheck.com/advisories/h3-before-2.0.1-rc.18-denial-of-service-via-unbounded-chunked-cookie

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-06 12:17

Updated : 2026-09-08 20:00

NVD link : CVE-2026-86250

Mitre link : CVE-2026-86250

CVE.ORG link : CVE-2026-86250

JSON object : View

Products Affected

No product.

CWE

CWE-400

Uncontrolled Resource Consumption

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