Hdfgroup Hdf5 vulnerabilities

CVE-2026-19029 Medium · 6.8 CWE-125 Oct 6, 2026

HDF5 scale-offset filter heap buffer over-read via crafted chunk

A heap-based buffer over-read in H5Z__filter_scaleoffset() in src/H5Zscaleoffset.c in HDF5 through 2.2.0 lets an attacker cause a denial of service (application crash) with a crafted HDF5 file. When the stored minimum bits equal the full precision of the datatype, the decoder copies d_nelmts * size bytes from the compressed chunk without checking that the chunk holds that many bytes. Both values come from attacker-controlled scale-offset filter parameters in the dataset's filter pipeline message.

CVE-2026-106547 High · 8.5 CWE-122 Oct 6, 2026

HDF5 heap buffer overflow in H5VM_array_fill via crafted fill-value metadata

A heap-based buffer overflow in H5VM_array_fill() in src/H5VM.c in HDF5 before 2.2.0 lets a remote attacker cause an application crash and possibly execute arbitrary code with a crafted HDF5 file. When a dataset's unallocated chunks are read, H5D__fill_init() fills the fill-value buffer from datatype and dataspace metadata in the file. If that metadata is inconsistent with the buffer's allocated size, the write goes past the end of the buffer. The attacker can control the content written through the fill value stored in the file.

CVE-2026-19028 Medium · 6.8 CWE-125 Aug 5, 2026

HDF5 integer underflow in Fletcher32 filter leads to massive out-of-bounds read

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.

CVE-2026-19027 Medium · 6.9 CWE-125 Aug 5, 2026

HDF5 out-of-bounds heap read in N-Bit filter decompression

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.

CVE-2026-19025 Medium · 6.8 CWE-369 Aug 5, 2026

HDF5 divide-by-zero (SIGFPE) via mismatched chunk-layout dimensionality and dataspace rank on dataset open

H5O__layout_decode in H5Olayout.c in HDF5 through 2.3.0 does not validate that a chunked dataset's stored chunk-layout dimensionality matches its dataspace rank when an existing dataset is opened, whereas this check is performed only at dataset-creation time. This allows attackers to cause a denial of service (divide-by-zero and application crash in H5S__hyper_iter_get_seq_list in src/H5Shyper.c) via a crafted HDF5 file with mismatched chunk/dataspace ranks that is opened and read via H5Dopen2 and H5Dread, e.g. by the h5repack tool.

CVE-2026-19024 High · 8.2 CWE-476 Aug 5, 2026

HDF5 H5Pget_fill_value NULL Pointer Dereference via Malformed Fill Value Message

NULL pointer dereference in H5Pget_fill_value in HDF5 before 2.3.0 allows attackers to cause a denial of service via a dataset whose version 1 or 2 fill value message has the "defined" flag set together with a negative size field, which is not normalized to the library's "undefined" sentinel and reaches H5T_path_find with a NULL datatype.

CVE-2026-19023 Medium · 6.8 CWE-822 Aug 5, 2026

HDF5 h5dump Untrusted Pointer Dereference in Binary Output of Variable-Length String Datasets

Untrusted pointer dereference in the render_bin_output function in the h5dump tool in HDF5 before 2.3.0 allows attackers to cause a denial of service via a variable-length string dataset with more than one element dumped in binary mode, which corrupts the per-element stride calculation and causes subsequent elements to be read from a misaligned offset and dereferenced as a pointer.

CVE-2026-19026 Medium · 6.8 CWE-476 Aug 5, 2026

Nbit filter NULL/short parameter-array dereference

H5Z__filter_nbit in H5Znbit.c in HDF5 prior to 2.3.0 dereferences cd_values[0] through cd_values[4] without validating that cd_values is non-NULL or that cd_nelmts is at least 5, the fixed size of the filter's header. This allows attackers to cause a denial of service via a crafted HDF5 file that stores the N-Bit filter pipeline message with zero client-data values, opened and read via H5Dread, e.g. by the h5ls or h5repack tools.

CVE-2026-17574 Medium · 5.5 CWE-476 Jul 27, 2026

NULL Pointer Dereference in HDF5 via Invalid Variable-Length Datatype Type Tag

HDF5 contains a NULL pointer dereference vulnerability. Processing a crafted HDF5 file containing an attribute with an invalid variable-length datatype type field may cause the application to crash when the attribute is read.

CVE-2026-17573 Medium · 5.5 CWE-415 Jul 27, 2026

Double Free in H5D__chunk_copy() in HDF5 via a Crafted Chunk-Index Size Field

A double free vulnerability was discovered in the HDF5 library. Processing a crafted HDF5 file containing an oversized chunk size field via h5repack may cause the application to abort due to a double free.

CVE-2026-17572 Medium · 5.5 CWE-125 Jul 27, 2026

HDF5 SOHM List Index Heap Buffer Overflow

Heap-based buffer overflow in the SOHM list-index deserialization code in HDF5 through 2.1.1 on all platforms allows attackers to cause a denial of service (crash) via a crafted HDF5 file whose shared-message list index declares a num_messages count exceeding list_max, triggering out-of-bounds heap reads and writes in H5SM__cache_list_deserialize and H5SM__cache_list_verify_chksum.

CVE-2026-26199 Medium · 6.5 CWE-124 Jul 20, 2026

Buffer underflow in `H5Iget_name `/`H5G_get_name` if size is zero

HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If `H5Iget_name` is invoked on a group id with `0` for the size parameter, it will underflow when trying to place a null terminator in the buffer. This can occur if `H5Iget_name` is invoked in a way where `size` can be forced to zero, and there is important data before the `name` buffer.

CVE-2026-26197 High · 7.5 CWE-125 Jul 20, 2026

Array full size, element count, and element size are not checked to make sure they match in H5Odtype.c

HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If a file is corrupted such that an array datatype's size, the number of elements, and the element size are not in agreement it can trigger an out of bounds read. The array datatype stores the full size of the datatype (`dt->shared->size`) separately from the number of elements (`dt->shared->u.array.nelem`) and the element size (`dt->shared->parent->shared->size`). If any one of these are corrupted so that they don't align with the others (element size * nelem = full size), it can lead to an out of bounds read. Depending on what is corrupted, it can alter the type of out of bounds read triggered. The vulnerability is present only in files that have been maliciously altered, as its generally not possible to independently alter the full size of the datatype, the element count and the element size. As such, this is only present if a malicious actor is altering files, and won't appear in regular usage.

CVE-2026-29043 Medium · 5.5 CWE-122 Apr 10, 2026

HDF5 H5T__ref_mem_setnull Heap Buffer Overflow

HDF5 is software for managing data. In 1.14.1-2 and earlier, an attacker who can control an h5 file parsed by HDF5 can trigger a write-based heap buffer overflow condition in the H5T__ref_mem_setnull method. This can lead to a denial-of-service condition, and potentially further issues such as remote code execution depending on the practical exploitability of the heap overflow against modern operating systems.

CVE-2026-34734 High · 7.8 CWE-416 Apr 9, 2026

HDF5: H5T__conv_struct Use After Free

HDF5 is software for managing data. In 1.14.1-2 and earlier, a heap-use-after-free was found in the h5dump helper utility. An attacker who can supply a malicious h5 file can trigger a heap use-after-free. The freed object is referenced in a memmove call from H5T__conv_struct. The original object was allocated by H5D__typeinfo_init_phase3 and freed by H5D__typeinfo_term.

CVE-2026-26200 High · 7.8 CWE-122 Feb 19, 2026

HDF5 Affected by H5T__conv_struct_opt Heap Buffer Overflow

HDF5 is software for managing data. Prior to version 1.14.4-2, an attacker who can control an `h5` file parsed by HDF5 can trigger a write-based heap buffer overflow condition. This can lead to a denial-of-service condition, and potentially further issues such as remote code execution depending on the practical exploitability of the heap overflow against modern operating systems. Real-world exploitability of this issue in terms of remote-code execution is currently unknown. Version 1.14.4-2 fixes the issue.