Junglewise Threat Intelligence

CVE-2026-40385: libexif integer overflow in Nikon MakerNote handling

CVE-2026-40385 · Severity: medium · CVSS 4 · Published 2026-04-12

Executive brief

A vulnerability exists in libexif, a widely used library for parsing metadata in image files. On 32-bit systems, a local attacker could use a specially crafted image to cause applications using this library to crash or potentially leak sensitive information from memory. This could impact the reliability of photo-processing software and the privacy of data handled by those applications.

Technical details

An integer overflow (CWE-190) exists in the Nikon MakerNote handling logic within libexif through version 0.6.25. Specifically, the addition of offsets during the parsing of Olympus/Nikon metadata (exif-mnote-data-olympus.c) can overflow on 32-bit systems where size_t is 32 bits. A local attacker can exploit this by providing a malformed EXIF payload, leading to out-of-bounds reads. This results in a denial-of-service (crash) or the disclosure of sensitive memory contents. A patch has been committed to the libexif repository to implement overflow checking before offset calculation.

Affected products

  • libexif project libexif up to and including 0.6.25

Timeline

  • 2026-04-12: disclosed: CVE-2026-40385 published
  • 2026-04-14: advisory: NIST initial analysis completed
  • 2026-04-12: patched: Fix committed to libexif GitHub repository

References

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