A flaw was discovered in the GIMP image editor’s PSD file format plugin. The vulnerability is an unsigned integer underflow in the `block_rem` variable, which occurs when a user opens a specially crafted .psd image file. The underflow causes the parser to misinterpret layer resource blocks, allowing an attacker to inject arbitrary data that can subsequently be executed, leading to arbitrary code execution on the victim’s system.

Red Hat Enterprise Linux distributions, specifically RHEL 6 through RHEL 9, run the affected version of GIMP that contains the unpatched PSD plugin. The CVE notes the affected operating systems rather than a specific GIMP release, implying that installation of GIMP on these platforms is vulnerable unless the vendor’s update is applied.

The CVSS score of 8.4 indicates high severity, while the EPSS score is not available and the vulnerability is not listed in CISA’s KEV catalog, suggesting a lower known exploitation probability. The attack vector is inferred to be local: an attacker would need to deliver a malicious .psd file that a user opens with GIMP, or compromise a system to place such a file. In the absence of a patch, the only feasible mitigation is to avoid opening untrusted or suspicious PSD files with GIMP.