CVE-2026-57075: YAML::Syck versions before 1.47 for Perl allow an out-of-bounds read via a signed-char lookup-table index in s

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CRITICAL 9.1REMOTE

CVE-2026-57075 is a critical-severity flaw (CVSS 9.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

YAML::Syck versions before 1.47 for Perl allow an out-of-bounds read via a signed-char lookup-table index in syck_base64dec. The base64 decoder in the bundled libsyck indexes the 256-entry static table b64_xtable with a signed char, so any !!binary byte >= 0x80 sign-extends to a negative index and reads before the table. The decoder receives the raw bytes of any !!binary node, a standard YAML type not gated by $LoadBlessed or $LoadCode, so it is

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-07-16
Last modified	2026-10-24

Publisher (CNA): CPANSec

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-07-16 22:17 UTCPublished CVE record published
2026-10-24 20:10 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · perl-Alien-Brotli · FIXED · 0.2.2-16.fc46 · FEDORA-2026-a2abe3db79 · source

sudo dnf upgrade --advisory=FEDORA-2026-a2abe3db79

Fedora ELN · mariadb-connector-odbc · FIXED · 3.2.10-1.eln159 · FEDORA-2026-b481dcd597 · source

sudo dnf upgrade --advisory=FEDORA-2026-b481dcd597

Debian 12 · libyaml-syck-perl · FIXED · 1.34-2+deb12u3

sudo apt update && sudo apt install --only-upgrade libyaml-syck-perl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libyaml-syck-perl)" ge "1.34-2+deb12u3" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · libyaml-syck-perl · FIXED · 1.34-2+deb13u3

sudo apt update && sudo apt install --only-upgrade libyaml-syck-perl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libyaml-syck-perl)" ge "1.34-2+deb13u3" && echo PATCHED || echo STILL-VULNERABLE

RHEL 6 · perl-YAML-Syck · DEFERRED

RHEL 7 · perl-YAML-Syck · DEFERRED

RHEL 8 · perl-YAML-Syck · DEFERRED

Alpine 3.24 · perl-yaml-syck · FIXED · perl-yaml-syck-1.47-r0

apk add --upgrade perl-yaml-syck apk info -v perl-yaml-syck

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-2007 · source

sudo dnf update --advisory=ALAS2023-2026-2007

Amazon Linux 2 · see advisory · FIXED · ALAS2-2026-3837 · source

sudo yum update --advisory=ALAS2-2026-3837

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-57075?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-57075 being exploited?

CVE-2026-57075 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-57075 affect?

CVE-2026-57075 affects affected software. Severity is critical (CVSS 9.1). YAML::Syck versions before 1.47 for Perl allow an out-of-bounds read via a signed-char lookup-table index in syck_base64dec. The base64 decoder in the bundled libsyck indexes the 256-entry static table b64_xtable with a signed char, so any

How urgent is CVE-2026-57075?

Priority 52/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Perl vulnerabilities

References

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