CVE-2026-21435

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Source
https://cve.org/CVERecord?id=CVE-2026-21435
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21435.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-21435
Aliases
Downstream
Related
Published
2026-02-12T18:22:58Z
Modified
2026-08-12T03:51:38Z
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
webtransport-go CloseWithError can block indefinitely
Details

webtransport-go is an implementation of the WebTransport protocol. Prior to v0.10.0, an attacker can cause a denial of service in webtransport-go by preventing or indefinitely delaying WebTransport session closure. A malicious peer can withhold QUIC flow control credit on the CONNECT stream, blocking transmission of the WT_CLOSE_SESSION capsule and causing the close operation to hang. This vulnerability is fixed in v0.10.0.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21435.json"
}
References

Affected packages

Git / github.com/quic-go/webtransport-go

Affected ranges

Type
GIT
Repo
https://github.com/quic-go/webtransport-go
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
9d448b125754f4c83064afb2c586221214e55eec
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:quic-go:webtransport-go:*:*:*:*:*:go:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.10.0"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

v0.*
v0.1.0
v0.2.0
v0.3.0
v0.4.0
v0.4.1
v0.4.2
v0.4.3
v0.5.0
v0.5.1
v0.5.2
v0.5.3
v0.6.0
v0.7.0
v0.8.0
v0.9.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21435.json"