Wasmtime vulnerable to data leakage between instances in the pooling allocator
Wasmtime is a standalone runtime for WebAssembly. Prior to versions 2.0.2 and 1.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator where when a linear memory is reused for another instance the initial heap snapshot of the prior instance can be visible, erroneously to the next instance. This bug has been patched and users should upgrade to Wasmtime 2.0.2 and 1.0.2. Other mitigations include disabling the pooling allocator and disabling the `memory-init-cow`.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2022-39393
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 2 Nov 2026, 17:12 UTC · Revision 1
Source evidence
Wasmtime vulnerable to data leakage between instances in the pooling allocator
core-osv · Original sourcePublished 10 Nov 2022, 00:00 UTC
Wasmtime is a standalone runtime for WebAssembly. Prior to versions 2.0.2 and 1.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator where when a linear memory is reused for another instance the initial heap snapshot of the prior instance can be visible, erroneously to the next instance. This bug has been patched and users should upgrade to Wasmtime 2.0.2 and 1.0.2. Other mitigations include disabling the pooling allocator and disabling the `memory-init-cow`.
osv:CVE-2022-39393
Complete source record
{
"id": "8f47b500e6e1188421a6c89309965eb950ec5de38d74ca7ff2c5d1c844c40530",
"url": "https://osv.dev/vulnerability/CVE-2022-39393",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Wasmtime vulnerable to data leakage between instances in the pooling allocator",
"summary": "Wasmtime is a standalone runtime for WebAssembly. Prior to versions 2.0.2 and 1.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator where when a linear memory is reused for another instance the initial heap snapshot of the prior instance can be visible, erroneously to the next instance. This bug has been patched and users should upgrade to Wasmtime 2.0.2 and 1.0.2. Other mitigations include disabling the pooling allocator and disabling the `memory-init-cow`.",
"evidence": "osv:CVE-2022-39393",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2022-39393",
"aliases": [
"CVE-2022-39393",
"GHSA-wh6w-3828-g9qf",
"RUSTSEC-2022-0075",
"RUSTSEC-2022-0098"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/bytecodealliance/wasmtime",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "15991947f485a60298e45d1d915125c0f3cc5a8a"
},
{
"introduced": "ff8c568eeed3918a5d591295e9384e2b1e462aae"
},
{
"fixed": "a528e0383e1177119a6c985dac1972513df11a03"
},
{
"fixed": "2614f2e9d2d36805ead8a8da0fa0c6e0d9e428a0"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "1.0.2"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*",
"range": [
{
"introduced": "2.0.0"
},
{
"fixed": "2.0.2"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "2614f2e9d2d36805ead8a8da0fa0c6e0d9e428a0"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"v1.0.1",
"v2.0.1",
"v2.0.0",
"v1.0.0",
"v0.35.0",
"v0.33.0",
"v0.34.0",
"v0.32.0",
"v0.31.0",
"v0.30.0",
"v0.29.0",
"v0.28.0",
"v0.27.0",
"v0.26.0",
"v0.25.0",
"v0.24.0",
"v0.23.0",
"v0.22.0",
"cranelift-v0.69.0",
"v0.21.0",
"v0.20.0",
"v0.19.0",
"v0.18.0",
"v0.17.0",
"v0.16.0",
"cranelift-v0.61.0",
"cranelift-v0.60.0",
"v0.12.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-39393.json"
}
}
],
"modified": "2026-10-28T02:30:21.771677638Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39393.json",
"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-wh6w-3828-g9qf",
"https://nvd.nist.gov/vuln/detail/CVE-2022-39393",
"https://github.com/bytecodealliance/wasmtime/commit/2614f2e9d2d36805ead8a8da0fa0c6e0d9e428a0"
],
"provider_metadata": {
"cwe_ids": [
"CWE-226"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39393.json"
}
},
"related_cves": [
{
"value": "CVE-2022-39393",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 487585,
"published_at": "2022-11-10T00:00:00+00:00"
}