Amazon Linux 2 (EOS) Security Advisory: ALAS2-2026-3871
Advisory Released Date: 2026-08-31
Advisory Updated Date: 2026-08-31
DBI versions before 1.652 for Perl allow a heap out-of-bounds write via an unvalidated numeric placeholder that sets the binder counter in preparse.
preparse reserves seven output bytes per input byte, the width of the longest ':p99999' expansion. The ':N' branch parses the number with `atoi(src)` and assigns it to the binder counter with no range check, so a statement containing ':2147483648' leaves the counter negative (-2147483648 with glibc, where atoi wraps). Each following '?' then expands through `sprintf(start, ":p%d", idx++)` to ':p-2147483648', 14 bytes with the terminating NUL where the buffer budgets 7. The placeholder limit added in 1.650 tests the counter against 99,999, which a negative counter passes.
Any caller that preparses an untrusted statement into ':pN' style placeholders gets a heap out-of-bounds write that grows with the number of '?' marks following the poisoned placeholder. The '?' and '%s' return styles compare the parsed number against the expected sequence and error out, and are unaffected. (CVE-2026-73194)
Affected Packages:
perl-DBI
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update perl-DBI or yum update --advisory ALAS2-2026-3871 to update your system.
aarch64:
perl-DBI-1.627-4.amzn2.0.7.aarch64
perl-DBI-debuginfo-1.627-4.amzn2.0.7.aarch64
i686:
perl-DBI-1.627-4.amzn2.0.7.i686
perl-DBI-debuginfo-1.627-4.amzn2.0.7.i686
src:
perl-DBI-1.627-4.amzn2.0.7.src
x86_64:
perl-DBI-1.627-4.amzn2.0.7.x86_64
perl-DBI-debuginfo-1.627-4.amzn2.0.7.x86_64