CVE-2026-86250

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Source
https://cve.org/CVERecord?id=CVE-2026-86250
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86250.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-86250
Aliases
Published
2026-09-06T12:00:26Z
Modified
2026-09-10T03:31:03Z
Severity
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
h3 before 2.0.1-rc.18 Denial of Service via Unbounded Chunked Cookie
Details

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.

Database specific 
{
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
        "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86250.json"
}
References

Affected packages

Git / github.com/h3js/h3

Affected ranges

Type
GIT
Repo
https://github.com/h3js/h3
Events
Introduced
62356d7964d2640b6bf7bbba457732fe944ed618
Fixed
cb70e1ba513be827bb3698127bb7d06467412911
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "2.0.0-beta.4"
        },
        {
            "fixed": "2.0.1-rc.18"
        },
        {
            "introduced": "0"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "DESCRIPTION"
    ]
}

Affected versions

v1.*
v1.15.8
v2.*
v2.0.0-beta.4
v2.0.0-beta.5
v2.0.0-rc.1
v2.0.1-rc.10
v2.0.1-rc.11
v2.0.1-rc.12
v2.0.1-rc.13
v2.0.1-rc.14
v2.0.1-rc.15
v2.0.1-rc.16
v2.0.1-rc.17
v2.0.1-rc.2
v2.0.1-rc.3
v2.0.1-rc.4
v2.0.1-rc.5
v2.0.1-rc.6
v2.0.1-rc.7
v2.0.1-rc.8
v2.0.1-rc.9

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86250.json"