DEBIAN-CVE-2026-56123

See a problem?
Please try reporting it to the source first.
Source
https://security-tracker.debian.org/tracker/CVE-2026-56123
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-56123.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-56123
Upstream
  • CVE-2026-56123
Published
2026-06-25T17:17:01Z
Modified
2026-09-14T17:03:20Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

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.

References

Affected packages

Debian:13 / socat

Package

Name
socat
Purl
pkg:deb/debian/socat?arch=source&distro=trixie

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.8.0.3-1+deb13u1

Affected versions

1.*
1.8.0.3-1

Ecosystem specific 

{
    "urgency":  "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-56123.json"

Debian:14 / socat

Package

Name
socat
Purl
pkg:deb/debian/socat?arch=source&distro=forky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.8.1.3-1

Affected versions

1.*
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

Ecosystem specific 

{
    "urgency":  "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-56123.json"