CVE catalog
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 syck_base64dec. The base64 decoder in the bundled libsyck indexes the 256-entry static tab
- Severity
- Critical · CVSS 9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.63% · Oct 25, 2026
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 reached on the default Load path. Any caller that runs Load or LoadFile on an untrusted document containing a !!binary scalar with a high-bit byte triggers the read, and the value read can surface in the decoded result.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | libyaml-syck-perl | sid | 1.47-1 | fixed |
| Debian | libyaml-syck-perl | forky | 1.47-1 | fixed |
| Debian | libyaml-syck-perl | trixie | 1.34-2+deb13u3 | fixed |
| Debian | libyaml-syck-perl | trixie-security | 1.34-2+deb13u3 | fixed |
| Debian | libyaml-syck-perl | bookworm | 1.34-2+deb12u2 | vulnerable |
| Debian | libyaml-syck-perl | bookworm-security | 1.34-2+deb12u3 | fixed |
| Cpe | libyaml-syck-perl | Not reported | Not reported | vulnerable |
| Alpine | perl-yaml-syck | 3.24 | 1.47-r0 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | libyaml-syck-perl | source | sid | 1.47-1 | not yet assigned | Not reported | [1142267] |
| Debian | libyaml-syck-perl | source | forky | 1.47-1 | not yet assigned | Not reported | [1142267] |
| Debian | libyaml-syck-perl | source | trixie | 1.34-2+deb13u3 | not yet assigned | Not reported | [1142267] |
| Debian | libyaml-syck-perl | source | bookworm | 1.34-2+deb12u3 | not yet assigned | Not reported | [1142267] |
| Alpine | perl-yaml-syck | apk | 3.24 | 1.47-r0 | Not reported | ALPINE-CVE-2026-57075 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libyaml-syck-perl]Affected
Details (4)
1.34-2+deb12u2· amd64 · bookwormAffected · Fixed:
1.34-2+deb12u3nvd · libyaml-syck-perl · debian · bookworm; nvd · libyaml-syck-perl · debian · 12
1.34-2+deb12u2· arm64 · bookwormAffected · Fixed:
1.34-2+deb12u3nvd · libyaml-syck-perl · debian · bookworm; nvd · libyaml-syck-perl · debian · 12
1.34-2+deb12u3· amd64 · bookworm-securityFixed · Fixed:
1.34-2+deb12u3nvd · libyaml-syck-perl · debian · bookworm; nvd · libyaml-syck-perl · debian · 12
1.34-2+deb12u3· arm64 · bookworm-securityFixed · Fixed:
1.34-2+deb12u3nvd · libyaml-syck-perl · debian · bookworm; nvd · libyaml-syck-perl · debian · 12
[Debian 13 (Trixie)]
- [libyaml-syck-perl]Affected
Details (5)
1.34-2+deb13u2· amd64 · trixieAffected · Fixed:
1.34-2+deb13u3nvd · libyaml-syck-perl · debian · 13
1.34-2+deb13u2· arm64 · trixieAffected · Fixed:
1.34-2+deb13u3nvd · libyaml-syck-perl · debian · 13
1.34-2+deb13u2· amd64 · trixie-security · Historical versionAffected · Fixed:
1.34-2+deb13u3nvd · libyaml-syck-perl · debian · 13
1.34-2+deb13u3· amd64 · trixie-securityFixed · Fixed:
1.34-2+deb13u3nvd · libyaml-syck-perl · debian · 13
1.34-2+deb13u3· arm64 · trixie-securityFixed · Fixed:
1.34-2+deb13u3nvd · libyaml-syck-perl · debian · 13
Observed:
References
- [http://www.openwall.com/lists/oss-security/2026/07/17/2]
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11299-1.json]
- [https://github.com/toddr/YAML-Syck/commit/44c90a109ec3215ee7ce747bd11209835e123d8b.patch]
- [https://metacpan.org/release/TODDR/YAML-Syck-1.47/changes]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-57075]
- [https://osv.dev/vulnerability/ALPINE-CVE-2026-57075]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-57075]
- [https://security-tracker.debian.org/tracker/CVE-2026-57075]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-57075.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2508.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]