host · socket.getaddrinfo() accepts embedded null bytes
Affects MicrosoftSource GCVE Database
Not known to be exploited · CVSS 5.3 Medium : upgrade to 3.16.0 when convenient.
Data as of 31 Oct 2026, 08:50 UTC
Thin evidence
One scorer or none| CNA (PSF) | CVSS 4.0 | 5.3 |
|---|
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.16.0
CVSS:4.0/AV:A/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 29 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade CPython to 3.16.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Python Software FoundationCPython | Affected
| Fixed in
|
GitHubCPythonpkg:github/CPythonOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
A vulnerability identified as CVE-2026-116566 affects Microsoft software version 3.0, where the socket.getaddrinfo() function improperly accepts embedded null bytes in the host and port parameters. This flaw relates to CWE-158, indicating improper handling of input data. No CVSS score or detailed impact information is provided, and there are no known exploits in the wild.