Technology · Bytecode Alliance
Bytecode Alliance Wasmtime vulnerabilities
Updated . Rebuilt every hour.
Junglewise Threat Intelligence has tracked 55 vulnerabilities in Bytecode Alliance Wasmtime: 0 in the last 7 days and 45 in the last 90 days, 4 of them critical and 0 exploited in the wild. The most recent, CVE-2026-121439, was published on 3 November 2026. 41 vulnerabilities in the last four weeks, up 925% on the four before (4). 3 critical against 0.
- Last 7 days
- 0
- Last 90 days
- 45
- Critical, all time
- 4
- Exploited in the wild
- 0
About Bytecode Alliance Wasmtime
WebAssembly runtime that executes compiled WebAssembly modules with support for system programming and server-side applications.
Latest Bytecode Alliance Wasmtime vulnerabilities
- CVE-2026-121439: Wasmtime wasi-http response splitting via unvalidated headersmediumCVSS 5.3
- CVE-2026-119143: Wasmtime denial of service in component model stream operationsmediumCVSS 4.8
- CVE-2026-119142: Wasmtime host panic in call_async Future dropmediumCVSS 4.8
- CVE-2026-119141: Wasmtime denial of service in realloc handlingmediumCVSS 5.3
- CVE-2026-119140: Wasmtime denial of service via thread.yield in component startmediumCVSS 4.8
- CVE-2026-119139: Wasmtime host crash in async-lifted function invocationmediumCVSS 4.8
- CVE-2026-119138: Wasmtime assertion failure after trap in pending callsmediumCVSS 4.8
- CVE-2026-119137: Wasmtime stack overflow in recursive type dropsmediumCVSS 5.3
- CVE-2026-119136: Wasmtime async-entrypoint enforcement bypassmediumCVSS 4.8
- CVE-2026-119135: Wasmtime panic in component model stream type mismatchmediumCVSS 4.8
- CVE-2026-119134: Wasmtime component-model resource handle unbounded memory growthmediumCVSS 6.2
- CVE-2026-119132: Wasmtime host panic via overlapping string transcode in fused adaptermediumCVSS 4.8
- CVE-2026-119131: Wasmtime denial of service in wasmtime-wasi-httpmediumCVSS 5.3
- Wasmtime unchecked memory usage in borrowed resource transferinfo
- Wasmtime type confusion with host-created struct typesinfo
- CVE-2026-118688: Wasmtime filesystem sandbox escape via symlink renamehighCVSS 7.9
- 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%
- CVE-2026-115392: Wasmtime filesystem sandbox escape via symlink trailing slasheshighCVSS 7.9
- CVE-2026-115391: Wasmtime WASIp3 uncontrolled resource allocation in streamsmediumCVSS 5.8
- CVE-2026-115390: Wasmtime fuel accounting bypass in call_ref and try_tablemediumCVSS 5.7
- CVE-2026-115388: Wasmtime wasmtime-wasi-http memory exhaustion in HTTP body writemediumCVSS 6.2
- CVE-2026-115387: Wasmtime denial of service via WASI filesystem timestamp overflowmediumCVSS 6.2
- CVE-2026-115385: Wasmtime denial of service in WASIp3 timestamp handlingmediumCVSS 6.2
Most severe Bytecode Alliance Wasmtime 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-2026-115384: Wasmtime stack buffer overflow in component async callbackscriticalCVSS 9.9
- CVE-2026-118688: Wasmtime filesystem sandbox escape via symlink renamehighCVSS 7.9
- CVE-2026-115392: Wasmtime filesystem sandbox escape via symlink trailing slasheshighCVSS 7.9
- 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-2026-35186: Bytecode Alliance Wasmtime out-of-bounds access in Winch compilerhighCVSS 7.5EPSS 0.2%
- CVE-2026-58494: Bytecode Alliance Wasmtime improper permission preservation in wasmtime-wasimediumCVSS 6.5EPSS 0.2%
Vulnerabilities per week
41 vulnerabilities in the last four weeks, up 925% on the four before (4). 3 critical against 0. The last 13 weeks, by the week each vulnerability was published.
| Week of | Bar | Vulns | Critical |
|---|---|---|---|
| 17 Aug 2026 | 0 | 0 | |
| 24 Aug 2026 | 0 | 0 | |
| 31 Aug 2026 | 0 | 0 | |
| 7 Sep 2026 | 0 | 0 | |
| 14 Sep 2026 | 0 | 0 | |
| 21 Sep 2026 | 1 | 0 | |
| 28 Sep 2026 | 3 | 0 | |
| 5 Oct 2026 | 0 | 0 | |
| 12 Oct 2026 | 9 | 0 | |
| 19 Oct 2026 | 16 | 3 | |
| 26 Oct 2026 | 15 | 0 | |
| 2 Nov 2026 | 1 | 0 | |
| 9 Nov 2026 | 0 | 0 |
Embed a badge
A live badge for a README, a status page or an internal wiki: how many Bytecode Alliance Wasmtime vulnerabilities were published in the last 7 days and how many of them are critical, refreshed hourly.
[](https://junglewise.ai/threats/technologies/bytecode-alliance-wasmtime)<a href="https://junglewise.ai/threats/technologies/bytecode-alliance-wasmtime"><img src="https://junglewise.ai/threats/technologies/bytecode-alliance-wasmtime/badge.svg" alt="Bytecode Alliance Wasmtime 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/bytecode-alliance-wasmtime.json, and this page as text at https://junglewise.ai/threats/technologies/bytecode-alliance-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, "Bytecode Alliance Wasmtime vulnerabilities", https://junglewise.ai/threats/technologies/bytecode-alliance-wasmtime, 11 November 2026.