Amazon Linux 2023 Security Advisory: ALAS2023-2026-1830
Advisory Released Date: 2026-06-22
Advisory Updated Date: 2026-06-22
Sereal::Decoder versions before 5.005 for Perl allow heap out-of-bounds read via crafted input.
In Perl/Decoder/srl_decoder.c, srl_read_object() and srl_read_hash() process a COPY tag, a back-reference whose target byte the decoder re-decodes as a fresh tag. When that target byte matches the SHORT_BINARY pattern (an inline string whose length is encoded in the low bits of the tag), the resulting read is not bounded to precede the COPY tag's own offset and can run past the end of the input buffer. An attacker controlled COPY offset can land inside a previously decoded value rather than on a tag boundary, planting a byte that the decoder reads as a SHORT_BINARY tag and consuming up to 31 following bytes from the heap as a class name (OBJECT path) or hash key (HASH path). (CVE-2026-8796)
Affected Packages:
perl-Sereal-Decoder
Issue Correction:
Run dnf update perl-Sereal-Decoder --releasever 2023.12.20260622 or dnf update --advisory ALAS2023-2026-1830 --releasever 2023.12.20260622 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation
aarch64:
perl-Sereal-Decoder-debuginfo-4.018-2.amzn2023.0.4.aarch64
perl-Sereal-Decoder-debugsource-4.018-2.amzn2023.0.4.aarch64
perl-Sereal-Decoder-4.018-2.amzn2023.0.4.aarch64
src:
perl-Sereal-Decoder-4.018-2.amzn2023.0.4.src
x86_64:
perl-Sereal-Decoder-debuginfo-4.018-2.amzn2023.0.4.x86_64
perl-Sereal-Decoder-4.018-2.amzn2023.0.4.x86_64
perl-Sereal-Decoder-debugsource-4.018-2.amzn2023.0.4.x86_64