StackPatch is liveSee product

Back to CVE digest
CVE-2021-28363 · cross-distro fix matrix

CVE-2021-28363: The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isn't given via proxy_config) doesn't verify the hostname of the certificate. This means certificates for d

Affects 8 Linux releases across 8 (distro × package) combinations.

Fix per ecosystem

Each block below is a distro release where CVE-2021-28363 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

  • python-urllib3→ fixed in1.26.4-1urgency: not yet assigned
    sudo apt-get install --only-upgrade -y python-urllib3

Debian bookworm

Source: Debian Security Tracker

  • python-urllib3→ fixed in1.26.4-1urgency: not yet assigned
    sudo apt-get install --only-upgrade -y python-urllib3

Debian trixie

Source: Debian Security Tracker

  • python-urllib3→ fixed in1.26.4-1urgency: not yet assigned
    sudo apt-get install --only-upgrade -y python-urllib3

Alpine v3.20

Source: Alpine secdb

  • py3-urllib3→ fixed in1.26.4-r0
    apk update && apk add --upgrade py3-urllib3

Alpine v3.21

Source: Alpine secdb

  • py3-urllib3→ fixed in1.26.4-r0
    apk update && apk add --upgrade py3-urllib3

Alpine edge

Source: Alpine secdb

  • py3-urllib3→ fixed in1.26.4-r0
    apk update && apk add --upgrade py3-urllib3

Alpine v3.18

Source: Alpine secdb

  • py3-urllib3→ fixed in1.26.4-r0
    apk update && apk add --upgrade py3-urllib3

Alpine v3.19

Source: Alpine secdb

  • py3-urllib3→ fixed in1.26.4-r0
    apk update && apk add --upgrade py3-urllib3
Are YOU affected by CVE-2021-28363?

5-second check on your actual server. Reads /etc/os-release, uname -r, and the distro's package manager; matches against this same cross-source index live.

curl https://mindsparkstack.com/scan.sh | bash
Form-based quickscan View on NVD
Continuous monitoring beats manual checking

CVE-2021-28363dropped silently in your distro's update channel. Every new CVE is the same story. StackPatch runs the matcher hourly against all 5 sources and emails the exact remediation when something new applies to one of your servers. $99 lifetime, 50 founder seats, 30-day refund.

See StackPatch ($99 lifetime)