CVE-2026-18300

A flaw was found in GIMP, specifically within the parsing of High Dynamic Range (HDR) files. This integer overflow vulnerability occurs due to insufficient validation of user-supplied data before memory allocation. A remote attacker could exploit this by convincing a user to open a specially crafted malicious HDR file, leading to arbitrary code execution in the context of the current process.

Red Hat Product Security rates this vulnerability as Important severity because successful exploitation allows arbitrary code execution in the target user's context, though it requires user interaction and does not grant direct privilege escalation. In Red Hat Enterprise Linux environments, GIMP is an optional desktop application rather than a background service, limiting potential attack vectors to interactive user workflows. Exploitation requires inducing a user to load an untrusted High Dynamic Range image file containing malformed dimensions, which triggers an arithmetic overflow in the image processing library during buffer allocation.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Users should exercise caution when opening HDR files from untrusted sources. It is recommended to only open HDR files from known and trusted origins to reduce the risk of exploitation. Additionally, consider running GIMP within a sandboxed environment if processing untrusted files is a regular activity.