CVE-2026-116566
socket.getaddrinfo() accepts embedded null bytes in host and port
Description
socket.getaddrinfo() previously accepted null bytes within *host* and *port* parameters which can cause the values to be silently truncated.
INFO
Published Date :
Oct. 29, 2026, 6:17 p.m.
Last Modified :
Oct. 29, 2026, 9:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-116566
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 28c92f92-d60d-412d-b760-e73465c3df22 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Apply system updates to fix socket parameter handling.
- Validate input for null bytes in host and port.
- Ensure truncation does not occur silently.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-116566.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-116566 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-116566
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-116566 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-116566 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Oct. 29, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/10/29/4 -
New CVE Received by [email protected]
Oct. 29, 2026
Action Type Old Value New Value Added Description socket.getaddrinfo() previously accepted null bytes within *host* and *port* parameters which can cause the values to be silently truncated. Added CVSS V4.0 AV:A/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-158 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/116xxx/CVE-2026-116566.json">CVE-2026-116566</a> Added Reference https://github.com/python/cpython/issues/160898 Added Reference https://github.com/python/cpython/pull/160899 Added Reference https://mail.python.org/archives/list/[email protected]/thread/HCHE62VYTPYI6WOPJQDWUBR4CINBPSM7/