Technology · crates.io
wasmtime (crates.io) vulnerabilities
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Junglewise Threat Intelligence has tracked 67 vulnerabilities in wasmtime (crates.io): 0 in the last 7 days and 28 in the last 90 days, 3 of them critical and 0 exploited in the wild. The most recent, Wasmtime type confusion with host-created struct types, was published on 29 October 2026. 21 vulnerabilities in the last four weeks, up 320% on the four before (5). 2 critical against 0.
- Last 7 days
- 0
- Last 90 days
- 28
- Critical, all time
- 3
- Exploited in the wild
- 0
About wasmtime (crates.io)
WebAssembly runtime environment for executing WebAssembly modules outside the browser.
Latest wasmtime (crates.io) vulnerabilities
- Wasmtime type confusion with host-created struct typesinfo
- RUSTSEC-2026-0422 - Typed functions with `i31` or `nullref` arguments may panic due to insufficient type-checklowCVSS 3.1
- Wasmtime unchecked memory usage in borrowed resource transferinfo
- CVE-2026-115893: Wasmtime Cranelift aarch64 br_table sandbox escapecriticalCVSS 9.9EPSS 1.0%
- CVE-2026-115892: Wasmtime component-model type-check bypass in stream/future loweringmediumCVSS 4EPSS 0.4%
- CVE-2026-115889: Wasmtime Cranelift SSA value index overflowcriticalCVSS 9.9EPSS 0.4%
- RUSTSEC-2026-0379 - Cranelift backend on aarch64 can jump to incorrect target on large Wasm `br_table` instructionlowCVSS 3.1
- RUSTSEC-2026-0380 - Bit-packing in Cranelift compiler causes silent overflow and miscompilationlowCVSS 3.1
- Wasmtime panic lowering host-created component model streammediumCVSS 4
- Wasmtime exception tags data structure alignment issuemediumCVSS 4
- RUSTSEC-2026-0359 - Stack overflow dropping a long chain of recursive typeslowCVSS 3.1
- Wasmtime host panic in call_async cancellationmediumCVSS 4
- Wasmtime component start function panicmediumCVSS 4
- Wasmtime panic when pending calls are run after a trapmediumCVSS 4
- Wasmtime async-entrypoint requirement enforcement bypassmediumCVSS 4
- Wasmtime overlapping string transcode panic in fused adaptermediumCVSS 4
- RUSTSEC-2026-0356 - Panic on erroneous call-to-host from guest realloc calllowCVSS 3.1
- Wasmtime component model panic on type mismatch viewing stream or futuremediumCVSS 4
- RUSTSEC-2026-0363 - Component-model handle tables are capped only per instance and charged to no limitlowCVSS 3.1
- Wasmtime panic when invoking async-lifted function via callmediumCVSS 4
- Wasmtime out-of-bounds zero-length stream writes panicmediumCVSS 4
- Wasmtime component async-lifted callback stack buffer overflowmediumCVSS 4
- Wasmtime WebAssembly tag import GC heap corruptionmediumCVSS 4
- RUSTSEC-2026-0326 - Rooting for GC values live across `try_call` may be missing, causing GC heap corruptionlowCVSS 3.1
- RUSTSEC-2026-0315 - `call_ref` and exception `catch` can drop some fuel accounting, leading to exponential fuel amplificationlowCVSS 3.1
Most severe wasmtime (crates.io) vulnerabilities
Exploited in the wild first, then by severity and CVSS score.
- CVE-2026-115893: Wasmtime Cranelift aarch64 br_table sandbox escapecriticalCVSS 9.9EPSS 1.0%
- CVE-2026-115889: Wasmtime Cranelift SSA value index overflowcriticalCVSS 9.9EPSS 0.4%
- CVE-2026-34987: Bytecode Alliance Wasmtime sandbox escape in Winch compiler backendcriticalCVSS 9.9EPSS 0.3%
- CVE-2026-34941: Wasmtime: Heap OOB read in component model UTF-16 to latin1+utf16 string transcodinghighCVSS 8.1EPSS 0.4%
- CVE-2026-34971: Bytecode Alliance Wasmtime sandbox escape in Cranelift backend on aarch64highCVSS 7.8EPSS 0.4%
- CVE-2026-44216: Bytecode Alliance Wasmtime denial of service via table allocation panichighCVSS 7.5EPSS 0.6%
- CVE-2026-34946: Wasmtime has host panic when Winch compiler executes `table.fill`highCVSS 7.5EPSS 0.4%
- CVE-2026-34943: Wasmtime has a possible panic when lifting `flags` component valuehighCVSS 7.5EPSS 0.3%
- CVE-2026-35186: Bytecode Alliance Wasmtime out-of-bounds access in Winch compilerhighCVSS 7.5EPSS 0.2%
- CVE-2026-34942: Wasmtime: Panic when transcoding misaligned utf-16 stringsmediumCVSS 6.5EPSS 0.4%
Vulnerabilities per week
21 vulnerabilities in the last four weeks, up 320% on the four before (5). 2 critical against 0. The last 13 weeks, by the week each vulnerability was published.
| Week of | Bar | Vulns | Critical |
|---|---|---|---|
| 17 Aug 2026 | 2 | 0 | |
| 24 Aug 2026 | 0 | 0 | |
| 31 Aug 2026 | 0 | 0 | |
| 7 Sep 2026 | 0 | 0 | |
| 14 Sep 2026 | 0 | 0 | |
| 21 Sep 2026 | 2 | 0 | |
| 28 Sep 2026 | 3 | 0 | |
| 5 Oct 2026 | 0 | 0 | |
| 12 Oct 2026 | 12 | 0 | |
| 19 Oct 2026 | 6 | 2 | |
| 26 Oct 2026 | 3 | 0 | |
| 2 Nov 2026 | 0 | 0 | |
| 9 Nov 2026 | 0 | 0 |
Embed a badge
A live badge for a README, a status page or an internal wiki: how many wasmtime (crates.io) vulnerabilities were published in the last 7 days and how many of them are critical, refreshed hourly.
[](https://junglewise.ai/threats/technologies/wasmtime)<a href="https://junglewise.ai/threats/technologies/wasmtime"><img src="https://junglewise.ai/threats/technologies/wasmtime/badge.svg" alt="wasmtime (crates.io) vulnerabilities" /></a>How this is built
Junglewise Threat Intelligence collects vulnerabilities from NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories, and matches each one to the technologies and vendors it affects. Dates are the date a vulnerability was published, in UTC.
The pages are rebuilt from the database every hour. Frozen weekly and monthly reports never change once published, so they can be cited.
Use this data
The same data is at https://junglewise.ai/threats/technologies/wasmtime.json, and this page as text at https://junglewise.ai/threats/technologies/wasmtime.md, for scripts and language models. It is free to reuse under CC BY 4.0 with a link back to this page.
Cite as: Junglewise Threat Intelligence, "wasmtime (crates.io) vulnerabilities", https://junglewise.ai/threats/technologies/wasmtime, 13 November 2026.