CVE-2026-35195

Source
https://cve.org/CVERecord?id=CVE-2026-35195
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-35195.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-35195
Aliases
Downstream
Related
Published
2026-04-09T18:55:56.467Z
Modified
2026-07-15T02:19:30.487320005Z
Severity
  • 6.1 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Wasmtime has an out-of-bounds write or crash when transcoding component model strings
Details

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime's implementation of transcoding strings between components contains a bug where the return value of a guest component's realloc is not validated before the host attempts to write through the pointer. This enables a guest to cause the host to write arbitrary transcoded string bytes to an arbitrary location up to 4GiB away from the base of linear memory. These writes on the host could hit unmapped memory or could corrupt host data structures depending on Wasmtime's configuration. Wasmtime by default reserves 4GiB of virtual memory for a guest's linear memory meaning that this bug will by default on hosts cause the host to hit unmapped memory and abort the process due to an unhandled fault. Wasmtime can be configured, however, to reserve less memory for a guest and to remove all guard pages, so some configurations of Wasmtime may lead to corruption of data outside of a guest's linear memory, such as host data structures or other guests's linear memories. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.

Database specific
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-787"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35195.json"
}
References

Affected packages

Git / github.com/bytecodealliance/wasmtime

Affected ranges

Type
GIT
Repo
https://github.com/bytecodealliance/wasmtime
Events
Database specific
{
    "source": [
        "CPE_RANGE",
        "CPE_STRING"
    ],
    "cpe": [
        "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*",
        "cpe:2.3:a:bytecodealliance:wasmtime:43.0.0:*:*:*:*: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"
        },
        {
            "last_affected": "43.0.0"
        }
    ]
}

Affected versions

43.*
43.0.0
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-2026-35195.json"