Executive brief
HDF5 is a widely-used library for managing large scientific datasets. A heap-use-after-free vulnerability in the floating-point conversion routine can be triggered when parsing a specially crafted HDF5 file containing a compound datatype. An attacker who can supply such a file can cause applications like h5dump to crash or, potentially, execute arbitrary code, affecting any service that processes untrusted HDF5 data.
Technical details
The vulnerability is a heap-use-after-free in the H5T__conv_f_f() function in src/H5Tconv.c, triggered during conversion of compound datatypes containing floating-point members. A temporary buffer is allocated via calloc() during dataset read operations, then freed and subsequently read from within the same conversion routine. The attack vector requires the attacker to supply a malicious HDF5 file that will be parsed by an application using the affected HDF5 library (versions prior to 1.14.2). The immediate impact is denial of service through a crash; depending on heap layout and allocator behavior, exploitation for memory corruption or remote code execution may be possible. A patch is available in HDF5 version 1.14.2 and later.
Affected products
- HDF Group HDF5 before 1.14.2
Timeline
- 2026-09-16: disclosed
- 2024-09-20: advisory: Pulse Security advisory published with PoC and fuzzing details