An out‑of‑bounds write flaw was discovered in the NTLM input handling code on Apple platforms. The flaw is triggered when the software processes specially crafted NTLM packets that bypass existing bounds checks, leading to memory corruption outside the intended buffer. Because the code fails to validate the size of the input correctly, a malformed packet can corrupt memory and cause the application that processes the NTLM data to terminate unexpectedly, resulting in a denial‑of‑service condition.

The vulnerability affects Apple devices running iOS, iPadOS, and macOS Golden Gate that have not been updated to version 27. Apple’s official advisory states that the issue was addressed with improved bounds checking in iOS 27, iPadOS 27 and macOS Golden Gate 27. The affected products are Apple iOS, Apple iPadOS and Apple macOS Golden Gate.

The CVE entry does not provide a CVSS score or EPSS value, and the vulnerability is not listed in the CISA KEV catalog. The attack vector is inferred to be an authenticated or unauthenticated NTLM authentication request sent to the device, which can be local or remote. Because the flaw only causes application termination, there is no evidence of privilege escalation or data exfiltration, but it can disrupt user experience and availability if exploited repeatedly. The absence of a published CVSS metric makes it difficult to quantify the severity, but the observed effect of a crash suggests a high impact on availability for the affected application.