CVE-2026-56123
HIGH
8.1
CVSS 3.1
Description
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.
Metadata
Severity & Metrics
8.1
HIGH CVSS 3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products (1)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| socat | socat | — | 1.8.0.0 < 1.8.1.2 |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| CWE-122 | cna | Heap-based Buffer Overflow |
CVSS scores (2)
| Score | Severity | Version | Source | Vector |
|---|---|---|---|---|
| 9.2 | CRITICAL | 4.0 | cna | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| 8.1 | HIGH | 3.1 | cna | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
References (2)