CVE-2026-34943

Source
https://cve.org/CVERecord?id=CVE-2026-34943
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34943.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-34943
Aliases
Downstream
Related
Published
2026-04-09T18:36:51.370Z
Modified
2026-07-15T01:48:53.590203338Z
Severity
  • 5.6 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Wasmtime panics when lifting `flags` component value
Details

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits should be ignored but Wasmtime will panic when this value is lifted. This panic only affects wasmtime's implementation of lifting into Val, not when using the flags! macro. This additionally only affects flags-typed values which are part of a WIT interface. This has the risk of being a guest-controlled panic within the host which Wasmtime considers a DoS vector. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.

Database specific
{
    "cwe_ids": [
        "CWE-248"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34943.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/bytecodealliance/wasmtime

Affected ranges

Type
GIT
Repo
https://github.com/bytecodealliance/wasmtime
Events
Database specific
{
    "cpe": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "24.0.7"
        },
        {
            "introduced": "25.0.0"
        },
        {
            "fixed": "36.0.7"
        },
        {
            "introduced": "37.0.0"
        },
        {
            "fixed": "42.0.2"
        },
        {
            "introduced": "43.0.0"
        },
        {
            "fixed": "43.0.1"
        }
    ],
    "source": "CPE_RANGE"
}

Affected versions

cranelift-v0.*
cranelift-v0.60.0
cranelift-v0.61.0
cranelift-v0.69.0
Other
dev
v0.*
v0.12.0
v0.16.0
v0.17.0
v0.18.0
v0.19.0
v0.20.0
v0.21.0
v0.22.0
v0.23.0
v0.24.0
v0.25.0
v0.26.0
v0.27.0
v0.28.0
v0.29.0
v0.30.0
v0.31.0
v0.32.0
v0.33.0
v0.34.0
v0.35.0
v24.*
v24.0.0
v24.0.1
v24.0.2
v24.0.3
v24.0.4
v24.0.5
v24.0.6
v36.*
v36.0.0
v36.0.1
v36.0.2
v36.0.3
v36.0.4
v36.0.5
v36.0.6
v42.*
v42.0.0
v42.0.1
v43.*
v43.0.0

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34943.json"