CVE-2025-21122 is an integer underflow vulnerability classified under CWE-191 affecting Adobe Photoshop Desktop versions 25.12, 26.1, and earlier. An integer underflow occurs when an arithmetic operation causes a value to wrap around below its minimum representable value, potentially leading to memory corruption or logic errors. In this case, the underflow can be triggered by processing a maliciously crafted file, causing Photoshop to mismanage memory buffers or internal data structures. This mismanagement can lead to arbitrary code execution within the context of the current user, allowing an attacker to run malicious code on the victim's system. Exploitation requires the victim to open a malicious file, meaning user interaction is necessary. The vulnerability does not require elevated privileges or prior authentication, increasing its risk profile. The CVSS v3.1 score of 7.8 reflects high impact on confidentiality, integrity, and availability, with low attack complexity but requiring user interaction. No known exploits have been reported in the wild, and Adobe has not yet released patches. The vulnerability is significant due to Photoshop's widespread use in creative industries and enterprises, making it a valuable target for attackers aiming to compromise workstations or steal intellectual property.

If exploited, this vulnerability could allow attackers to execute arbitrary code with the same privileges as the logged-in user, potentially leading to data theft, installation of malware, or further network compromise. The impact spans confidentiality (unauthorized data access), integrity (modification of files or system state), and availability (disruption of Photoshop or system operations). Since Photoshop is widely used in creative, media, and corporate environments, exploitation could result in intellectual property theft, disruption of business operations, and potential lateral movement within networks. The requirement for user interaction limits mass exploitation but targeted attacks against high-value individuals or organizations remain a significant risk. The absence of patches increases exposure time, and attackers may develop exploits once the vulnerability details become widely known.

Until Adobe releases an official patch, organizations should implement the following mitigations: 1) Educate users to avoid opening files from untrusted or unknown sources, especially unsolicited attachments or downloads. 2) Disable or restrict automatic file previews in email clients and file explorers to prevent accidental triggering of the vulnerability. 3) Employ endpoint protection solutions with heuristic and behavior-based detection to identify suspicious Photoshop activity. 4) Use application whitelisting to limit execution of unauthorized code. 5) Monitor network and host logs for unusual behavior indicative of exploitation attempts. 6) Prepare to deploy patches promptly once Adobe releases updates. 7) Consider isolating Photoshop usage to segmented environments or virtual machines to contain potential compromise. 8) Regularly back up critical data to enable recovery in case of successful exploitation.