> A comment on it from Christian Helms adds: > > Just to stress one point: users must update pip to >= 26.2.2. > > > > pip always loads the CA certificates from its vendored certifi in > > addition to the system trust store, and there is no supported way to > > disable this. REQUESTS_CA_BUNDLE / --cert only add CAs; truststore is > > used “in addition to certifi” by design. As a result, any pip < 26.2.2 > > will keep trusting the compromised intermediate CAs regardless of the > > system trust store, so distrusting them at the OS level is not enough.
The discuss.python.org conversation on that issue has long since moved on, so asking here: The macOS remediation advice on the official vuln page at https://emudhra.we-have-a-problem.com/#macos-curl lists remediation instructions which it is claimed address this, with instructions to set a PIP_CERT environment variable in a sitecustomize.py file. > The built-in pip3, and the pip in virtual environments created from the > built-in python3, use their own outdated copy of the roots instead. To make > them use the fixed system file, run: > > F="$(/usr/bin/python3 -c 'import sysconfig; > print(sysconfig.get_path("stdlib"))')/sitecustomize.py" && echo 'import os; os.environ.setdefault("PIP_CERT", "/etc/ssl/cert.pem")' | sudo tee -a "$F" > /dev/null && sudo chmod 644 "$F" I'm finding it a bit tricky to figure out a reproducible test case which would exercise this, so I haven't done more testing myself, but—does this actually work? Or is upgrading `pip` to >= 26.2.2 the only solution? (Or, now that `pip` > 26.2.2 is out, is upgrading the better solution, and I should go file a PR against the site to update its guidance.) (Incidentally, the latest macOS updates do _NOT_ include an updated `/etc/ssl/cert.pem`, and do clobber any manual changes you or your IT department may have made to `/etc/ssl/cert.pem`, so any manual mitigations you have applied to remove the AAA Certificate Services and emSign ECC Root CA - G3 certs _DO_ need to be reapplied.) Best, - Kevin On Thu, Oct 22, 2026 at 4:43 PM Alan Coopersmith <[email protected]> wrote: > > https://discuss.python.org/t/information-for-python-users-regarding-emudhra-emsign-ca-certificate-security-incident/109576 > has this statement from Seth Michael Larson: > > A security incident affecting eMudhra intermediate certificates has > > required removing the emSign root CA certificate from CA bundles such > > as “certifi”. It’s important to immediately upgrade the software > > packages below to at least the versions specified and rebuild > > container images with layer caching disabled to fetch the latest > > system certificates. Failure to do so could result in > > monster-in-the-middle (MITM) attacks against TLS clients, including > > python.org and pypi.org . > > > > certifi 2026.10.19 (1) > > pip 26.2.2 > > uv 0.13.4 > > sigstore 4.5.1 > > conda 26.9.4 > > pixi 0.82.1 > > > > (1): Advisory mentions 2026.10.18, but 2026.10.19 is recommended for > > compatibility with unaffected emSign root certificates. > > > > For all existing virtual environments on your system, please upgrade > > pip and uv to the latest versions. You can update pip securely by > > running the following command and then use this secure pip > > installation to upgrade certifi and uv: > > > > python -m pip install "pip @ > > https://files.pythonhosted.org/packages/3f/06/3e4420302363fbb71be3c7f35ce042f54bfca330e3e66b3a2e3c4cca579f/pip-26.2.2-py3-none-any.whl#sha256=fd7f4dfa8190e014013b9f08f3e973f4e4c26ffd179a204895533a7254813a70"; > > > > Note that the certifi CA bundle is included in the macOS installation > > of Python from python.org. To upgrade certificates for this > > installation and pip itself, run the command below like so: > > > > /Library/Frameworks/Python.framework/Versions/3.15/bin/python3.15 -m pip > > install "pip @ > > https://files.pythonhosted.org/packages/3f/06/3e4420302363fbb71be3c7f35ce042f54bfca330e3e66b3a2e3c4cca579f/pip-26.2.2-py3-none-any.whl#sha256=fd7f4dfa8190e014013b9f08f3e973f4e4c26ffd179a204895533a7254813a70"; > > /Library/Frameworks/Python.framework/Versions/3.15/bin/python3.15 -m pip > > install --upgrade certifi > > /Library/Frameworks/PythonT.framework/Versions/3.15/bin/python3.15t -m pip > > install "pip @ > > https://files.pythonhosted.org/packages/3f/06/3e4420302363fbb71be3c7f35ce042f54bfca330e3e66b3a2e3c4cca579f/pip-26.2.2-py3-none-any.whl#sha256=fd7f4dfa8190e014013b9f08f3e973f4e4c26ffd179a204895533a7254813a70"; > > > > This topic will be updated as more information is made available. > > A comment on it from Christian Helms adds: > > Just to stress one point: users must update pip to >= 26.2.2. > > > > pip always loads the CA certificates from its vendored certifi in > > addition to the system trust store, and there is no supported way to > > disable this. REQUESTS_CA_BUNDLE / --cert only add CAs; truststore is > > used “in addition to certifi” by design. As a result, any pip < 26.2.2 > > will keep trusting the compromised intermediate CAs regardless of the > > system trust store, so distrusting them at the OS level is not enough. > > > > uv users can block the bad certs in their system trust store and > > UV_SYSTEM_CERTS=true. That does not work with pip. Updating pip is the > > only reliable fix. See Switch to using truststore only by default > > (currently mixed certifi + truststore) · Issue #14374 · pypa/pip · > > GitHub > > > > PS: The ‘security incident’ is a bad private key. An elliptic key with > > private key value d=4 is not secure… All 8 eMudhra CAs had private > > keys with d < 256. > > -- Kevin Riggle - Principal, Complex Systems Group LLC he/him • Brooklyn, NY, USA • Eastern Time https://complexsystems.group • https://calendly.com/kevinriggle/coffee
