CVE-2026-4177 · cross-distro fix matrix

CVE-2026-4177: YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter. The heap overflow occurs when class names exceed the initial 512-byte allocation. The base64 decoder could read past the buffer end on traili

Affects 4 Linux releases across 4 (distro × package) combinations.

Fix per ecosystem

Each block below is a distro release where CVE-2026-4177 has a known fix. Run the listed command on that distro to remediate.

Debian bullseye

Source: Debian Security Tracker

libyaml-syck-perl→ fixed in1.34-1+deb11u1urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y libyaml-syck-perl
```

Debian bookworm

Source: Debian Security Tracker

libyaml-syck-perl→ fixed in1.34-2+deb12u2urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y libyaml-syck-perl
```

Debian trixie

Source: Debian Security Tracker

libyaml-syck-perl→ fixed in1.34-2+deb13u2urgency: not yet assigned
```
sudo apt-get install --only-upgrade -y libyaml-syck-perl
```

Alpine edge

Source: Alpine secdb

perl-yaml-syck→ fixed in1.45-r0

apk update && apk add --upgrade perl-yaml-syck

Are YOU affected by CVE-2026-4177?

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-2026-4177dropped 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)