Critical
mruby — security advisory
In mruby 2.1.0, there is a use-after-free in hash_values_at in mrbgems/mruby-hash-ext/src/hash-ext.c.
- Products
- mruby
- Affected versions
- 1.1.0+20150817+gita1731254-1, 1.1.0+20150906+git1cbbb7e1-1, 1.2.0+20160315+git4f20d58a-1, 1.3.0+20170925+git38185028-1, 1.3.0+20171029+git77edafb0-1, 1.3.0-1, 1.4.0-1, 2.0.0-1, 2.1.2-3, 3.0.0-1, 3.0.0-3, 3.2.0-1, 3.2.0-2, 3.3.0-1, 3.4.0-2, 3.4.0-3, 4.0.0-1
- Fixed versions
- Not specified
- CVEs
- CVE-2020-6838
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 01:29 UTC · Revision 1
Source evidence
In mruby 2.1.0, there is a use-after-free in hash_values_at in mrbgems/mruby-hash-ext/src/hash-ext.c.
osv:UBUNTU-CVE-2020-6838
mruby
Fixed versions: Not specified
mruby
Fixed versions: Not specified
mruby
Fixed versions: Not specified
mruby
Fixed versions: Not specified
mruby
Fixed versions: Not specified
mruby
Fixed versions: Not specified
mruby
Fixed versions: Not specified
mruby
Fixed versions: Not specified
Complete source record
{
"id": "32480dad2ee53d0ed19d194fa360d9deb9259462e12aa77901cfc056f4862987",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2020-6838",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2020-6838",
"summary": "In mruby 2.1.0, there is a use-after-free in hash_values_at in mrbgems/mruby-hash-ext/src/hash-ext.c.",
"evidence": "osv:UBUNTU-CVE-2020-6838",
"products": [
{
"name": {
"value": "mruby",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "1.1.0+20150817+gita1731254-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.1.0+20150906+git1cbbb7e1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.2.0+20160315+git4f20d58a-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
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"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
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"evidence": "/affected/1/versions"
},
{
"value": "1.3.0+20170925+git38185028-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.3.0+20171029+git77edafb0-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.4.0-1",
"evidence": "/affected/1/versions"
}
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},
{
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},
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{
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"evidence": "/affected/2/versions"
}
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},
{
"name": {
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"evidence": "/affected/3/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "2.1.2-3",
"evidence": "/affected/3/versions"
},
{
"value": "3.0.0-1",
"evidence": "/affected/3/versions"
},
{
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"evidence": "/affected/3/versions"
}
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{
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"affected_versions": [
{
"value": "3.2.0-1",
"evidence": "/affected/4/versions"
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{
"value": "3.2.0-2",
"evidence": "/affected/4/versions"
}
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},
{
"name": {
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"evidence": "/affected/5/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
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},
{
"name": {
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"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.4.0-2",
"evidence": "/affected/6/versions"
},
{
"value": "3.4.0-3",
"evidence": "/affected/6/versions"
},
{
"value": "4.0.0-1",
"evidence": "/affected/6/versions"
}
]
},
{
"name": {
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"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.3.0-1",
"evidence": "/affected/7/versions"
},
{
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"evidence": "/affected/7/versions"
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]
}
],
"severity": "critical",
"structured": {
"id": "UBUNTU-CVE-2020-6838",
"aliases": [
"UBUNTU-CVE-2020-6838"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "mruby",
"purl": "pkg:deb/ubuntu/mruby?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
"versions": [
"1.1.0+20150817+gita1731254-1",
"1.1.0+20150906+git1cbbb7e1-1",
"1.2.0+20160315+git4f20d58a-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-6838.json"
},
"ecosystem_specific": {
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"binary_version": "1.2.0+20160315+git4f20d58a-1"
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},
{
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"package": {
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"purl": "pkg:deb/ubuntu/mruby?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"1.3.0-1",
"1.3.0+20170925+git38185028-1",
"1.3.0+20171029+git77edafb0-1",
"1.4.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-6838.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "mruby",
"binary_version": "1.4.0-1"
}
]
}
},
{
"ranges": [
{
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"events": [
{
"introduced": "0"
}
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}
],
"package": {
"name": "mruby",
"purl": "pkg:deb/ubuntu/mruby?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"2.0.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-6838.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "mruby",
"binary_version": "2.0.0-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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"package": {
"name": "mruby",
"purl": "pkg:deb/ubuntu/mruby?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
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"3.0.0-1",
"3.0.0-3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-6838.json"
},
"ecosystem_specific": {
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{
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{
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},
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"3.2.0-1",
"3.2.0-2"
],
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"purl": "pkg:deb/ubuntu/mruby?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"3.3.0-1"
],
"database_specific": {
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},
"ecosystem_specific": {
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{
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}
]
}
},
{
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{
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"name": "mruby",
"purl": "pkg:deb/ubuntu/mruby?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"3.4.0-2",
"3.4.0-3",
"4.0.0-1"
],
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},
"ecosystem_specific": {
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{
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}
]
}
},
{
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"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"3.3.0-1",
"3.4.0-2"
],
"database_specific": {
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},
"ecosystem_specific": {
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"binary_version": "3.4.0-2"
}
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}
],
"modified": "2026-10-17T12:56:58.426386884Z",
"provider": "osv",
"upstream": [
"CVE-2020-6838"
],
"references": [
"https://ubuntu.com/security/CVE-2020-6838",
"https://github.com/mruby/mruby/issues/4926",
"https://github.com/mruby/mruby/commit/fc8fb41451b07b3fda0726ba80e88e509ad02452",
"https://github.com/mruby/mruby/commit/70e574689664c10ed2c47581999cc2ce3e3c5afb",
"https://github.com/mruby/mruby/commit/2742ded32fe18f88833d76b297f5c2170b6880c3",
"https://www.cve.org/CVERecord?id=CVE-2020-6838"
]
},
"related_cves": [
{
"value": "CVE-2020-6838",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 356585,
"published_at": "2020-01-11T03:15:00+00:00"
}