CVE-2026-126410
Wasmtime 48.0.0 before 48.0.8 TOCTOU UDP Send Policy Bypass via wasip3 Sockets
CVSS Score
6.4
EPSS Score
0.0%
EPSS Percentile
0th
Wasmtime's wasmtime-wasi crate 48.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a time-of-check/time-of-use race in the wasip3 wasi:sockets udp-socket host implementation that lets guests bypass socket_addr_check send restrictions. A malicious guest can race udp-socket.send against udp-socket.connect to deliver attacker-controlled datagrams to addresses the policy permits only for receiving.
| CWE | CWE-367 |
| Vendor | bytecodealliance |
| Product | wasmtime |
| Published | Nov 13, 2026 |
Stay Ahead of the Next One
Get instant alerts for bytecodealliance wasmtime
Be the first to know when new medium vulnerabilities affecting bytecodealliance wasmtime are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Affected Versions
bytecodealliance / wasmtime
48.0.0 < 48.0.8
bytecodealliance / wasmtime
49.0.0 < 49.0.5
bytecodealliance / wasmtime
50.0.0 < 50.0.1
References
Credits
🔍 las7 rvolosatovs