# CVE-2026-115381: rust-wasmtime: Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an unbounded memory allocation in th...

CVE-2026-115381 is fixed in rust-wasmtime on 1 platform by DEBIAN-CVE-2026-115381 (version 36.0.20+dfsg-1), released November 3, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-115381
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0021
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 22, 2026

## Description

Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an unbounded memory allocation in the wasmtime-wasi WASIp2 write-zeroes method of SinkOutputStream, the default stream used when stdout/stderr are not configured. A malicious WebAssembly guest can request huge zero-filled writes, exhausting host memory and causing denial of service.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rust-wasmtime Debian 14 | 36.0.20+dfsg-1 | [DEBIAN-CVE-2026-115381](https://patchblox.com/security/data/fix/linux/debian-cve-2026-115381.md) | Nov 3, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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