# Bytecodealliance Wasmtime vulnerabilities

Source: https://junglewise.ai/threats/technologies/bytecodealliance-wasmtime  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Updated: 9 November 2026, 03:07 UTC. Rebuilt every hour.  
Data: https://junglewise.ai/threats/technologies/bytecodealliance-wasmtime.json  
License: CC BY 4.0 with a link back

Junglewise Threat Intelligence has tracked 12 vulnerabilities in Bytecodealliance Wasmtime: 0 in the last 7 days and 0 in the last 90 days, 1 of them critical and 0 exploited in the wild. The most recent, CVE-2026-35195, was published on 9 April 2026.

## Counts

- Last 7 days: 0
- Last 30 days: 0
- Last 90 days: 0
- All time: 12 (1 critical, 0 exploited in the wild)

## About Bytecodealliance Wasmtime

Runtime for executing WebAssembly modules outside of web browsers.

## Latest Bytecodealliance Wasmtime vulnerabilities

- [CVE-2026-35195: Bytecode Alliance Wasmtime out-of-bounds write in string transcoding](https://junglewise.ai/threats/cve-2026-35195-bytecode-alliance-wasmtime-out-of-bounds-write-in-string) (medium, CVSS 5.4, published 9 Apr 2026)
- [CVE-2026-35186: Bytecode Alliance Wasmtime out-of-bounds access in Winch compiler](https://junglewise.ai/threats/cve-2026-35186-bytecode-alliance-wasmtime-out-of-bounds-access-in-winch-compiler) (high, CVSS 7.5, published 9 Apr 2026)
- [CVE-2026-34988: Bytecode Alliance Wasmtime data leakage in pooling allocator](https://junglewise.ai/threats/cve-2026-34988-bytecode-alliance-wasmtime-data-leakage-in-pooling-allocator) (medium, CVSS 6.3, published 9 Apr 2026)
- [CVE-2026-34987: Bytecode Alliance Wasmtime sandbox escape in Winch compiler backend](https://junglewise.ai/threats/cve-2026-34987-bytecode-alliance-wasmtime-sandbox-escape-in-winch-compiler) (critical, CVSS 9.9, published 9 Apr 2026)
- [CVE-2026-34983: Bytecode Alliance Wasmtime use-after-free in Linker cloning](https://junglewise.ai/threats/cve-2026-34983-bytecode-alliance-wasmtime-use-after-free-in-linker-cloning) (medium, CVSS 5, published 9 Apr 2026)
- [CVE-2026-34946: Wasmtime has host panic when Winch compiler executes `table.fill`](https://junglewise.ai/threats/cve-2026-34946-wasmtime-has-host-panic-when-winch-compiler-executes-table-fill) (high, CVSS 7.5, published 9 Apr 2026)
- [CVE-2026-34945: Wasmtime has host data leakage with 64-bit tables and Winch](https://junglewise.ai/threats/cve-2026-34945-wasmtime-has-host-data-leakage-with-64-bit-tables-and-winch) (medium, CVSS 6.5, published 9 Apr 2026)
- [CVE-2026-34944: Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64](https://junglewise.ai/threats/cve-2026-34944-wasmtime-segfault-or-unused-out-of-sandbox-load-with-f64x2-splat) (medium, CVSS 5.7, published 9 Apr 2026)
- [CVE-2026-34943: Wasmtime has a possible panic when lifting `flags` component value](https://junglewise.ai/threats/cve-2026-34943-wasmtime-has-a-possible-panic-when-lifting-flags-component-value) (high, CVSS 7.5, published 9 Apr 2026)
- [CVE-2026-34942: Wasmtime: Panic when transcoding misaligned utf-16 strings](https://junglewise.ai/threats/cve-2026-34942-wasmtime-panic-when-transcoding-misaligned-utf-16-strings) (medium, CVSS 6.5, published 9 Apr 2026)
- [CVE-2026-34941: Wasmtime: Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding](https://junglewise.ai/threats/cve-2026-34941-wasmtime-heap-oob-read-in-component-model-utf-16-to-latin1-utf16) (high, CVSS 8.1, published 9 Apr 2026)
- [CVE-2025-62711: RUSTSEC-2025-0112 - Possible host crash with host-to-wasm component intrinsics](https://junglewise.ai/threats/cve-2025-62711-wasmtime-vulnerable-to-segfault-when-using-component-resources) (medium, CVSS 4, published 24 Oct 2025)

## Most severe Bytecodealliance Wasmtime vulnerabilities

- [CVE-2026-34987: Bytecode Alliance Wasmtime sandbox escape in Winch compiler backend](https://junglewise.ai/threats/cve-2026-34987-bytecode-alliance-wasmtime-sandbox-escape-in-winch-compiler) (critical, CVSS 9.9, published 9 Apr 2026)
- [CVE-2026-34941: Wasmtime: Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding](https://junglewise.ai/threats/cve-2026-34941-wasmtime-heap-oob-read-in-component-model-utf-16-to-latin1-utf16) (high, CVSS 8.1, published 9 Apr 2026)
- [CVE-2026-34946: Wasmtime has host panic when Winch compiler executes `table.fill`](https://junglewise.ai/threats/cve-2026-34946-wasmtime-has-host-panic-when-winch-compiler-executes-table-fill) (high, CVSS 7.5, published 9 Apr 2026)
- [CVE-2026-34943: Wasmtime has a possible panic when lifting `flags` component value](https://junglewise.ai/threats/cve-2026-34943-wasmtime-has-a-possible-panic-when-lifting-flags-component-value) (high, CVSS 7.5, published 9 Apr 2026)
- [CVE-2026-35186: Bytecode Alliance Wasmtime out-of-bounds access in Winch compiler](https://junglewise.ai/threats/cve-2026-35186-bytecode-alliance-wasmtime-out-of-bounds-access-in-winch-compiler) (high, CVSS 7.5, published 9 Apr 2026)
- [CVE-2026-34942: Wasmtime: Panic when transcoding misaligned utf-16 strings](https://junglewise.ai/threats/cve-2026-34942-wasmtime-panic-when-transcoding-misaligned-utf-16-strings) (medium, CVSS 6.5, published 9 Apr 2026)
- [CVE-2026-34945: Wasmtime has host data leakage with 64-bit tables and Winch](https://junglewise.ai/threats/cve-2026-34945-wasmtime-has-host-data-leakage-with-64-bit-tables-and-winch) (medium, CVSS 6.5, published 9 Apr 2026)
- [CVE-2026-34988: Bytecode Alliance Wasmtime data leakage in pooling allocator](https://junglewise.ai/threats/cve-2026-34988-bytecode-alliance-wasmtime-data-leakage-in-pooling-allocator) (medium, CVSS 6.3, published 9 Apr 2026)
- [CVE-2026-34944: Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64](https://junglewise.ai/threats/cve-2026-34944-wasmtime-segfault-or-unused-out-of-sandbox-load-with-f64x2-splat) (medium, CVSS 5.7, published 9 Apr 2026)
- [CVE-2026-35195: Bytecode Alliance Wasmtime out-of-bounds write in string transcoding](https://junglewise.ai/threats/cve-2026-35195-bytecode-alliance-wasmtime-out-of-bounds-write-in-string) (medium, CVSS 5.4, published 9 Apr 2026)

## Vulnerabilities per week

Nothing was published in the last eight weeks.

| Week of | Vulns | Critical | Exploited |
| --- | --- | --- | --- |
| 17 Aug 2026 | 0 | 0 | 0 |
| 24 Aug 2026 | 0 | 0 | 0 |
| 31 Aug 2026 | 0 | 0 | 0 |
| 7 Sep 2026 | 0 | 0 | 0 |
| 14 Sep 2026 | 0 | 0 | 0 |
| 21 Sep 2026 | 0 | 0 | 0 |
| 28 Sep 2026 | 0 | 0 | 0 |
| 5 Oct 2026 | 0 | 0 | 0 |
| 12 Oct 2026 | 0 | 0 | 0 |
| 19 Oct 2026 | 0 | 0 | 0 |
| 26 Oct 2026 | 0 | 0 | 0 |
| 2 Nov 2026 | 0 | 0 | 0 |
| 9 Nov 2026 | 0 | 0 | 0 |

## Sources

NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "Bytecodealliance Wasmtime vulnerabilities", https://junglewise.ai/threats/technologies/bytecodealliance-wasmtime, 9 November 2026.