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Vulnerability · Published Jul 21, 2026 · Assigned by GitHub_M

CVE-2026-47667CImg Library: Uncontrolled Memory Allocation and Memory Leak in `_load_analyze()` via Crafted NIfTI/Analyze Header

High 7.5

In plain English

A high-severity memory leak in CImg from GreycLab. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.5%top 55.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12cimgno fix listedDEBIAN-CVE-2026-47667
Debian:13cimgno fix listedDEBIAN-CVE-2026-47667
Debian:14cimg4.0.4+dfsg-1DEBIAN-CVE-2026-47667
Ubuntu:26.04:LTScimgno fix listedUBUNTU-CVE-2026-47667
Ubuntu:26.10cimgno fix listedUBUNTU-CVE-2026-47667

Affected products (as reported)

VendorProductVersions
GreycLab CImg < 4.0.0

Weakness: CWE-401, CWE-789, CWE-1284 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References