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6.9 Medium

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

Description

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.

CVSS 4.0 detail

Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

Exploitable remotely over the network, with an ordinary account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
Low
Interaction
Passive
Confidentiality
None
Integrity
None
Availability
High
Confidentiality of other systems
None
Integrity of other systems
None
Availability of other systems
High

Affected products and versions

Product Affected versions Fixed in
wasmtime 47.0 47.0.0 → < 47.0.4 47.0.4
wasmtime 46.0 46.0.0 → < 46.0.3 46.0.3
The 81 CVEs of wasmtime →
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