Amazon Linux 2023 Security Advisory: ALAS2023-2026-1769
Advisory Released Date: 2026-06-08
Advisory Updated Date: 2026-06-08
Severity:
Medium
Issue Overview:
YAML::Syck versions before 1.38 for Perl has an out-of-bounds read.
The base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When processing the leftmost segment of a colon-separated value (e.g., the 1 in 1:30:45), the inner while loop can decrement a pointer past the start of the string buffer:
while ( colon >= ptr && *colon != ':' )
{
colon--;
}
if ( *colon == ':' ) *colon = '\0'; // colon may be ptr-1 here
When no colon is found (final/leftmost segment), colon becomes ptr-1, and the subsequent *colon dereference reads one byte before the allocated buffer. (CVE-2026-5089)
Affected Packages:
perl-YAML-Syck
Issue Correction:
Run dnf update perl-YAML-Syck --releasever 2023.12.20260608 or dnf update --advisory ALAS2023-2026-1769 --releasever 2023.12.20260608 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation
New Packages:
aarch64:
perl-YAML-Syck-debuginfo-1.37-1.amzn2023.0.3.aarch64
perl-YAML-Syck-debugsource-1.37-1.amzn2023.0.3.aarch64
perl-YAML-Syck-1.37-1.amzn2023.0.3.aarch64
perl-YAML-Syck-tests-1.37-1.amzn2023.0.3.aarch64
src:
perl-YAML-Syck-1.37-1.amzn2023.0.3.src
x86_64:
perl-YAML-Syck-debuginfo-1.37-1.amzn2023.0.3.x86_64
perl-YAML-Syck-debugsource-1.37-1.amzn2023.0.3.x86_64
perl-YAML-Syck-1.37-1.amzn2023.0.3.x86_64
perl-YAML-Syck-tests-1.37-1.amzn2023.0.3.x86_64