CVE-2026-19028
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:
None
VI:
None
VA:
High
Description
H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 prior to 2.3.0 computes the data length to checksum by subtracting the 4-byte trailing checksum size from the input buffer size without checking that the buffer is at least 4 bytes, allowing a size_t underflow. This allows attackers to cause a denial of service (massively out-of-bounds read and application crash in H5_checksum_fletcher32) via a crafted HDF5 file with a Fletcher32-filtered chunk smaller than 4 bytes, triggered via H5Dread, e.g. by the h5ls or h5dump tools.