CPython getaddrinfo accepts embedded null bytes (CVE-2026-116566)
Python's security list rates the socket.getaddrinfo host and port flaw medium; the notice is truncated.
48
CVE-2026-116566
Null-byte truncation in CPython socket.getaddrinfo()
- CVSS 4.0
- 5.3 medium
- EPSS
- —
- Published
- ·
- Modified
AI analysisSummaries by Vani AI
CPython’s socket.getaddrinfo() accepted embedded null bytes in the host and port arguments and could silently truncate those values. An attacker who can supply those parameters may cause name resolution to use a shortened host or port. The flaw is in CPython; Python has not listed affected builds.
What to do: Python has not listed a fixed version. Apply CPython’s update for CVE-2026-116566 when it is published.
| Product | Affected |
|---|---|
| Python CPython | — |
Estimated exposure
No basis for an estimate.
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description · NVD
socket.getaddrinfo() previously accepted null bytes within *host* and *port* parameters which can cause the values to be silently truncated.
- Weakness
- CWE-158
- Vector
- CVSS:4.0/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