CVE-2026-115391
Wasmtime 46.0.0 before 46.0.3 and 47.0.0 before 47.0.4 Unbounded Heap Allocation via WASIp3 Streams
CVSS Score
5.8
EPSS Score
0.0%
EPSS Percentile
0th
Wasmtime 46.0.0 before 46.0.3 and 47.0.0 before 47.0.4 contains an uncontrolled resource allocation vulnerability in its WASIp3 implementation that buffers guest-specified-length writes on the host without limit. Malicious guests can offer large buffers to WASIp3 file or HTTP write streams, causing the host to copy and buffer all bytes, bounded only by guest linear memory, exhausting host memory.
| CWE | CWE-770 |
| Vendor | bytecodealliance |
| Product | wasmtime |
| Published | Oct 22, 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:H/PR:L/UI:R/S:C/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
bytecodealliance / wasmtime
46.0.0 < 46.0.3 47.0.0 < 47.0.4
References
Credits
tschneidereit