CVE-2026-19027
MEDIUM
MEDIUM
Priority: 0.01
BB Relevance:
39/100
Published: 2026-08-06
Modified: 2026-10-23
First seen: 2026-10-29
Status: active
Attack Surface
Low Complexity
No Auth
CVSS Vector Breakdown
AV:
Local
AC:
Low
PR:
None
UI:
Passive
S:
X
AT:
None
VC:
Low
VI:
None
VA:
High
Description
The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 prior to 2.3.0 advance a read index into the compressed chunk buffer without bounding it against the buffer's actual size. This allows attackers to cause an out-of-bounds heap read, and in constrained cases disclosure of adjacent heap memory into decompressed dataset values, via a crafted HDF5 file whose N-Bit filter parameters describe more decompressed data than the stored compressed chunk actually contains, triggered via H5Dread, e.g. by the h5ls or h5repack tools.