Attack Chain

1. Attacker crafts a malicious image file specifically designed to trigger the out-of-bounds read vulnerability in Adobe Photoshop.
2. The attacker delivers the crafted file to the victim via email, shared drive, or other means.
3. The victim, unaware of the malicious nature of the file, opens it using a vulnerable version of Adobe Photoshop (27.4 or earlier).
4. Photoshop attempts to parse the crafted image file.
5. Due to the malformed structure of the file, Photoshop’s parsing routine attempts to read data beyond the allocated buffer.
6. The out-of-bounds read occurs, potentially exposing sensitive information or causing a crash.
7. An attacker leverages the out-of-bounds read to gain control of program execution flow.
8. The attacker executes arbitrary code within the context of the user running Photoshop, potentially leading to system compromise.

Impact

Successful exploitation of CVE-2026-27289 can lead to arbitrary code execution on the victim’s machine. Since the code runs within the user’s context, the attacker gains the same privileges as the user. This could enable the attacker to install malware, steal sensitive data, or pivot to other systems on the network. While the specific number of affected users isn’t specified, all users running versions 27.4 and earlier are potentially vulnerable, with the most likely targets being graphic designers, photographers, and other creative professionals.

Recommendation

• Upgrade Adobe Photoshop to a version greater than 27.4 to patch CVE-2026-27289.
• Implement user awareness training to educate users about the risks of opening files from untrusted sources to mitigate the initial access vector.
• Monitor process creation events for suspicious Photoshop processes using the provided Sigma rule to detect potential exploitation attempts.
• Enable file access monitoring to identify instances where Photoshop opens unusual or suspicious files, which could be indicative of malicious activity.