CVE-2026-44433

Source
https://cve.org/CVERecord?id=CVE-2026-44433
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44433.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-44433
Aliases
  • GHSA-f7qr-4p37-9gx9
Published
2026-07-16T22:23:17.247Z
Modified
2026-07-19T03:30:59.659434122Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
Quicly is vulnerable to memory exhaustion
Details

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, an adversarial peer could send a STREAM frame carrying just one byte at the largest offset being permitted to obtain additional flow control credit, which under certain circumstances could lead to a Denial of Service. Assuming the application prepares a receive buffer for storing all data that arrive out-of-order, up to the largest offset being received, this behavior could lead to the application allocating large amount of memory with the peer sending only a handful of packets, resulting in memory exhaustion. In addition to the receive buffer allocation strategy, the severity of this vulnerability depends on how the application controls the stream concurrency. In case of the H2O HTTP server, under its default setting, this bug increases the maximum amount of memory allocated per connection by about 4 times. This issue has been fixed by commit 8b178e6.

Database specific
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44433.json",
    "cna_assigner": "GitHub_M",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "fixed": "8b178e6"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ],
    "cwe_ids": [
        "CWE-400",
        "CWE-770"
    ]
}
References

Affected packages

Git / github.com/h2o/quicly

Affected ranges

Type
GIT
Repo
https://github.com/h2o/quicly
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
Database specific
{
    "source": "REFERENCES"
}

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44433.json"