Description

sammy846

opened on Jun 3, 2026

Issue body actions

Description:
Environment
OS: Windows 10/11

Python Version: 3.12.12

Package Manager: uv (v0.149.16 fails, v0.149.12 works)

Describe the bug
When upgrading zeroconf to version 0.149.16 on Windows, importing the library fails with an ImportError: DLL load failed while importing _cache: Access is denied. error. Downgrading the package back to 0.149.12 completely resolves the issue, indicating a potential regression introduced in the built C-extensions (_cache.pyd) in the latest release wheel.

Steps to Reproduce
Create/use a Python 3.12 environment on Windows.

Force reinstall version 0.149.16.

Try to import the library via terminal.

uv pip install --force-reinstall "zeroconf==0.149.16"
python -c "import zeroconf"

It appears something changed regarding file tracking, code signing, or how the binary wheels for _cache are compiled/distributed for Windows in the latest iteration.

Activity

1. bokjo commented on Jun 12, 2026

   

   bokjo

   on Jun 12, 2026

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   We had a similar issue yesterday, the security system flagged and blocked the exe from starting that includes the zeroconf cache DLL (zeroconf_cache.cp313-win_amd64.pyd).

   Application information:
   Application name:	Python
   Application version:	3.13.13150.1013
   Application publisher:	Python Software Foundation
   Process ID:	31352
   Application location:	C:\Users\[REDACTED]\AppData\Local\[REDACTED]\python\python.exe
   Command line:	"C:\Users\[REDACTED]\AppData\Local\[REDACTED]\python\python.exe" C:\Users\[REDACTED]\AppData\Local\[REDACTED]\python/Scripts/config.exe create
   File origin:	Hard drive on this computer
   
   Prevention information:
   Prevention date:	Thursday, 11 June 2026
   Prevention time:	08:38:36
   OS version:	10.0.26100.2.0.0.256.1
   Component:	Hash Control
   Status code:	c0400058
   Prevention description:	Suspicious DLL detected
   Additional information 1:	C:\Users\[REDACTED]\AppData\Local\[REDACTED]\python\Lib\site-packages\zeroconf\_cache.cp313-win_amd64.pyd
   Additional information 2:	D26F276CBAAA652E0B35A3688304E69180031808F6DABC1C09FF9BC7596B1D19
   Additional information 3:	D26F276CBAAA652E0B35A3688304E69180031808F6DABC1C09FF9BC7596B1D19
   Additional information 4:	1
   Additional information 6:	{"trigger":2,"component":309,"cystatus":3225419864,"filePath":"C:\\Users\\[REDACTED]\\AppData\\Local\\[REDACTED]\\python\\Lib\\site-packages\\zeroconf\\_cache.cp313-win_amd64.pyd","fileHash":{"sha256":"D26F276CBAAA652E0B35A3688304E69180031808F6DABC1C09FF9BC7596B1D19","sha1":"62CD21AEF60686888F57611205FE0FBD242EA485","md5":"5EA3BC6B68BA772BE723987906530EC2"},"streamHash":{"sha256":"D26F276CBAAA652E0B35A3688304E69180031808F6DABC1C09FF9BC7596B1D19","sha1":"62CD21AEF60686888F57611205FE0FBD242EA485","md5":"5EA3BC6B68BA772BE723987906530EC2"},"verdict":1,"fileType":2,"fileSize":"186368","streamFileType":2,"streamSize":"186368"}
   
2. bdraco commented on Jun 12, 2026

   

   bdraco

   on Jun 12, 2026

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   Package checks out and tests pass with this version so maybe it's some type of malware scanner hitting a false positive
3. bokjo commented on Jun 12, 2026

   

   bokjo

   on Jun 12, 2026

   More actions

   Package checks out and tests pass with this version so maybe it's some type of malware scanner hitting a false positive

   This indeed is coming from Palo Alto Cortex XDR, pinned to 0.147.4 for now, as a workaround solves the issue!

   Has something changed in your release/bundle pipeline recently (signing/certs)?

   This started happening with last week's bundles on our side, will try to understand from which version onwards!
4. bdraco commented on Jun 12, 2026

   

   bdraco

   on Jun 12, 2026

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   I don't think anything has changed besides the cython version

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