DEBIAN-CVE-2026-56123
socat versions 1.8.0.0 through 1.8.1.1 contain a heap-based buffer overflow vulnerability that allows a malicious SOCKS5 proxy server to overwrite adjacent heap memory by exploiting a sign-extension flaw in the DOMAINNAME reply parser. During connection setup, the domain name length byte is read through a signed char field causing a negative bytes_to_read value that is implicitly converted to size_t, resulting in an unbounded heap write into the 262-byte reply buffer with attacker-controlled size and content.
DEBIAN-CVE-2026-56123
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-56123
socat
Source reference: /affected/0/package/name
- Affected versions
- 1.8.0.3-1
Source reference:
/affected/0/versions - Fixed versions
- 1.8.0.3-1+deb13u1
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
socat
Source reference: /affected/1/package/name
- Affected versions
- 1.8.0.3-1
Source reference:
/affected/1/versions1.8.1.0-1Source reference:
/affected/1/versions1.8.1.0-2Source reference:
/affected/1/versions1.8.1.1-1Source reference:
/affected/1/versions1.8.1.1-2Source reference:
/affected/1/versions - Fixed versions
- 1.8.1.3-1
Source reference:
/affected/1/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.0.3-1+deb13u1"
}
]
}
],
"package": {
"name": "socat",
"purl": "pkg:deb/debian/socat?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.8.0.3-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-56123.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.1.3-1"
}
]
}
],
"package": {
"name": "socat",
"purl": "pkg:deb/debian/socat?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.8.0.3-1",
"1.8.1.0-1",
"1.8.1.0-2",
"1.8.1.1-1",
"1.8.1.1-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-56123.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #57918 · Revision 1
- Added to Heist Feed
- Publisher date