Alpine: multiple perl-yaml-syck packages: security update to 1.47-r0

critical Tenable Cloud Security Plugin ID 446244

Description

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

- YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed
while still on the parser value stack. In the bundled libsyck, when an anchor name is redefined or
removed, syck_hdlr_add_anchor and syck_hdlr_remove_anchor free the node stored under that name with
syck_free_node. That node can still be live on the parser's value stack, so syck_hdlr_add_node reaches it
again and frees it a second time. On a normal build the 48-byte node chunk is freed twice and the
interpreter aborts. Anchors need no special flags, so this is reached on the default Load path, and a
7-byte document that redefines an anchor triggers it. Any caller that runs Load or LoadFile on an
untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service.
(CVE-2026-13713)

- 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. (CVE-2026-57075)

- YAML::Syck versions before 1.47 for Perl allow a heap use-after-free via an anchor name reused as an
anchors-table key in syck_hdlr_add_anchor. In the bundled libsyck an anchor name allocated by syck_strndup
is stored both as node->anchor, freed when the node is freed, and as the key in the parser's anchors
table. Freeing the node frees the shared key, and a later anchor redefinition makes st_delete compare
against the freed key, so st_strcmp reads freed heap memory. Anchors are a standard YAML feature and need
no special flags, so this is reached on the default Load path. Any caller that runs Load or LoadFile on an
untrusted document that redefines an anchor reaches the read of freed memory. (CVE-2026-57076)

- YAML::Syck versions before 1.47 for Perl allow an out-of-bounds read via an unbounded newline scan in
newline_len. In the bundled libsyck newline_len and is_newline dereference the scan pointer, and the
following byte for a "\r\n" pair, with no NUL-terminator or bounds check. During block-scalar lexing at a
document boundary the scan runs one byte past the heap lexer buffer. This is an incomplete fix of
CVE-2025-11683, on a lexer path the earlier fix did not cover. Any caller that runs Load or LoadFile on an
untrusted document with a block scalar at a document boundary reaches the over-read. (CVE-2026-57077)

Solution

Update the perl-yaml-syck library and its related packages to version 1.47-r0 or later.

Plugin Details

Severity: Critical

ID: 446244

Version: Revision 1.1

Type: Local

Family: Alpine Linux Local Security Checks

Published: 8/23/2026

Updated: 8/23/2026

Supported Sensors: Agentless Assessment

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.89

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:C

CVSS Score Source: CVE-2026-57075

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 7/14/2026

Reference Information

CVE: CVE-2026-13713, CVE-2026-57075, CVE-2026-57076, CVE-2026-57077

Detections

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