High
golang-github-klauspost-compress — security advisory
compress provides various compression algorithms. Prior to version 1.18.7, a signed integer overflow vulnerability in s2.NewDict() allows an attacker to bypass repeat index validation by supplying a dictionary with a uvarint-encoded repeat value exceeding MaxInt64. When Dict.Encode() is subsequently called, the overflowed negative repeat value causes an out-of-bounds memory access via unsafe.Pointer arithmetic, crashing the process with SIGSEGV. This issue has been patched in version 1.18.7.
- Products
- golang-github-klauspost-compress
- Affected versions
- 0.0~git20151221.0.2dd54ae-1, 1.11.7-2, 1.15.12+ds1-3, 1.17.7+ds1-1, 1.18.0+ds1-1, 1.18.1+ds1-1, 1.19.0+ds1-1, 1.2.1-1, 1.2.1-2, 1.2.1-4, 1.2.1-5, 1.20.0+ds1-1, 1.7.6-2, 1.9.5-1, 1.9.5-2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-63209
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:49 UTC · Revision 1
Source evidence
compress provides various compression algorithms. Prior to version 1.18.7, a signed integer overflow vulnerability in s2.NewDict() allows an attacker to bypass repeat index validation by supplying a dictionary with a uvarint-encoded repeat value exceeding MaxInt64. When Dict.Encode() is subsequently called, the overflowed negative repeat value causes an out-of-bounds memory access via unsafe.Pointer arithmetic, crashing the process with SIGSEGV. This issue has been patched in version 1.18.7.
osv:UBUNTU-CVE-2026-63209
golang-github-klauspost-compress
Fixed versions: Not specified
golang-github-klauspost-compress
Fixed versions: Not specified
golang-github-klauspost-compress
Fixed versions: Not specified
golang-github-klauspost-compress
Fixed versions: Not specified
golang-github-klauspost-compress
Fixed versions: Not specified
golang-github-klauspost-compress
Fixed versions: Not specified
golang-github-klauspost-compress
Fixed versions: Not specified
Complete source record
{
"id": "2221f4b47f614894d73b2d4455c1457469bc9c01b7eec41e0c976a6935b00f6c",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-63209",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-63209",
"summary": "compress provides various compression algorithms. Prior to version 1.18.7, a signed integer overflow vulnerability in s2.NewDict() allows an attacker to bypass repeat index validation by supplying a dictionary with a uvarint-encoded repeat value exceeding MaxInt64. When Dict.Encode() is subsequently called, the overflowed negative repeat value causes an out-of-bounds memory access via unsafe.Pointer arithmetic, crashing the process with SIGSEGV. This issue has been patched in version 1.18.7.",
"evidence": "osv:UBUNTU-CVE-2026-63209",
"products": [
{
"name": {
"value": "golang-github-klauspost-compress",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "0.0~git20151221.0.2dd54ae-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "golang-github-klauspost-compress",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.2.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.2.1-2",
"evidence": "/affected/1/versions"
},
{
"value": "1.2.1-4",
"evidence": "/affected/1/versions"
},
{
"value": "1.2.1-5",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "golang-github-klauspost-compress",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.2.1-5",
"evidence": "/affected/2/versions"
},
{
"value": "1.7.6-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.9.5-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.9.5-2",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "golang-github-klauspost-compress",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.11.7-2",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "golang-github-klauspost-compress",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.15.12+ds1-3",
"evidence": "/affected/4/versions"
},
{
"value": "1.17.7+ds1-1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "golang-github-klauspost-compress",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.18.1+ds1-1",
"evidence": "/affected/5/versions"
},
{
"value": "1.19.0+ds1-1",
"evidence": "/affected/5/versions"
},
{
"value": "1.20.0+ds1-1",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "golang-github-klauspost-compress",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.18.0+ds1-1",
"evidence": "/affected/6/versions"
},
{
"value": "1.18.1+ds1-1",
"evidence": "/affected/6/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2026-63209",
"aliases": [
"UBUNTU-CVE-2026-63209"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "golang-github-klauspost-compress",
"purl": "pkg:deb/ubuntu/golang-github-klauspost-compress?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
"versions": [
"0.0~git20151221.0.2dd54ae-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63209.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "golang-github-klauspost-compress-dev",
"binary_version": "0.0~git20151221.0.2dd54ae-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "golang-github-klauspost-compress",
"purl": "pkg:deb/ubuntu/golang-github-klauspost-compress?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"1.2.1-1",
"1.2.1-2",
"1.2.1-4",
"1.2.1-5"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63209.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "golang-github-klauspost-compress-dev",
"binary_version": "1.2.1-5"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "golang-github-klauspost-compress",
"purl": "pkg:deb/ubuntu/golang-github-klauspost-compress?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"1.2.1-5",
"1.7.6-2",
"1.9.5-1",
"1.9.5-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63209.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "golang-github-klauspost-compress-dev",
"binary_version": "1.9.5-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "golang-github-klauspost-compress",
"purl": "pkg:deb/ubuntu/golang-github-klauspost-compress?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"1.11.7-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63209.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "golang-github-klauspost-compress-dev",
"binary_version": "1.11.7-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "golang-github-klauspost-compress",
"purl": "pkg:deb/ubuntu/golang-github-klauspost-compress?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"1.15.12+ds1-3",
"1.17.7+ds1-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63209.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "golang-github-klauspost-compress-dev",
"binary_version": "1.17.7+ds1-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "golang-github-klauspost-compress",
"purl": "pkg:deb/ubuntu/golang-github-klauspost-compress?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"1.18.1+ds1-1",
"1.19.0+ds1-1",
"1.20.0+ds1-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63209.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "golang-github-klauspost-compress-dev",
"binary_version": "1.20.0+ds1-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "golang-github-klauspost-compress",
"purl": "pkg:deb/ubuntu/golang-github-klauspost-compress?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"1.18.0+ds1-1",
"1.18.1+ds1-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63209.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "golang-github-klauspost-compress-dev",
"binary_version": "1.18.1+ds1-1"
}
]
}
}
],
"modified": "2026-10-17T12:59:15.594493912Z",
"provider": "osv",
"upstream": [
"CVE-2026-63209"
],
"references": [
"https://ubuntu.com/security/CVE-2026-63209",
"https://www.cve.org/CVERecord?id=CVE-2026-63209",
"https://github.com/klauspost/compress/commit/539243b8823ee8f03e49969823d57c348c917536",
"https://github.com/klauspost/compress/releases/tag/v1.18.7",
"https://github.com/klauspost/compress/security/advisories/GHSA-259r-337f-4rfw"
]
},
"related_cves": [
{
"value": "CVE-2026-63209",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 359563,
"published_at": "2026-09-29T15:17:00+00:00"
}