CVE-2016-4554 · cross-distro fix matrix

CVE-2016-4554: mime_header.cc in Squid before 3.5.18 allows remote attackers to bypass intended same-origin restrictions and possibly conduct cache-poisoning attacks via a crafted HTTP Host header, aka a "header smuggling" issue.

Affects 3 Linux releases across 3 (distro × package) combinations.

Elevated exploitation risk

FIRST EPSS puts CVE-2016-4554's probability of exploitation in the next 30 days at 39% (98th percentile of all CVEs)— well above the noise floor. Prioritize it.

EPSS:39% · 30-day exploit probability98th percentile

Fix per ecosystem

Each block below is a distro release where CVE-2016-4554 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

squid→ fixed in4.1-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y squid
```

Debian bookworm

Source: Debian Security Tracker

squid→ fixed in4.1-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y squid
```

Debian trixie

Source: Debian Security Tracker

squid→ fixed in4.1-1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y squid
```

Are YOU affected by CVE-2016-4554?

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

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