GreycLab CImg prior 4.0.0 Analyze NIfTI _load_analyze header_size allocation of resources

Summaryinfo

A vulnerability labeled as critical has been found in GreycLab CImg prior 4.0.0. This affects the function _load_analyze of the component Analyze NIfTI Handler. The manipulation of the argument header_size results in allocation of resources. This vulnerability was named CVE-2026-47667. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in GreycLab CImg prior 4.0.0. It has been classified as critical. Affected is the function _load_analyze of the component Analyze NIfTI Handler. The manipulation of the argument header_size with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

CImg Library is a C++ library for image processing. Prior to version 4.0.0 in `_load_analyze()`, the header_size field is read as an `unsigned int` from the first 4 bytes of an Analyze/NIfTI file and passed directly to `new unsigned char[header_size]` without being bounded against the actual file size. A value up to ~4 GB is accepted. If the subsequent `fread` returns `short` as it will for any malformed file), the function throws a `CImgIOException` and the allocated buffer is never freed. A 6-byte crafted file is sufficient to trigger an allocation of ~1.3 GB per call, with the full allocation leaked on every error path. The issue is reachable via `load_analyze()` and the generic `load()` when the file extension is .hdr, .img, or .nii. Version 4.0.0 fixes the issue.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-47667 since 05/19/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 4.0.0 eliminates this vulnerability.

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Productinfo

Vendor

• GreycLab

Name

• CImg

Version

• <4.0.0

Website

• Product: https://github.com/GreycLab/CImg/

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