Home/CVE/webtransport-go is an implementation of the WebTransport protocol. Prior to v0.10.0, an attacker can cause a denial of s
CVE

CVE-2026-21435

webtransport-go is an implementation of the WebTransport protocol. Prior to v0.10.0, an attacker can cause a denial of s

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.

MEDIUM · CVSS 5.3 EPSS 0.0002
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-400Uncontrolled Resource Consumption
▤

Affected Products & Versions

1
quic-go webtransport-go< 0.10.0
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Go github.com/quic-go/webtransport-go MODERATE fixed in 0.10.0
▣

Scoring & Timeline

5.3
MEDIUM · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD12 Feb 2026 · 07:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/quic-go/webtransport-go/releases/tag/v0.10.0ProductRelease Notes
https://github.com/quic-go/webtransport-go/security/advisories/GHSA-px4r-g4p3-hhqvVendor Advisory
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin