HDF Group HDF5 up to 2.3.0 H5Zfletcher32.c H5Z__filter_fletcher32 out-of-bounds

Summaryinfo

A vulnerability classified as critical has been found in HDF Group HDF5 up to 2.3.0. Affected by this vulnerability is the function H5Z__filter_fletcher32 of the file H5Zfletcher32.c. The manipulation leads to out-of-bounds. This vulnerability is documented as CVE-2026-19028. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in HDF Group HDF5 up to 2.3.0. It has been rated as critical. This issue affects the function H5Z__filter_fletcher32 of the file H5Zfletcher32.c. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 through 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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-19028 since 08/06/2026. The exploitation is known to be easy. The attack may be initiated remotely. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-53676). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Database Software

Vendor

• HDF Group

Name

• HDF5

Version

• 2.0
• 2.1
• 2.2
• 2.3.0

License

• free

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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