Red Hat Hivex OOB Read via Malformed Registry Hive
CVE-2026-120740 Published on November 2, 2026
Hivex: hivex: denial of service via out-of-bounds read in big-data block processing
A flaw was found in hivex. By supplying a specially crafted Windows registry hive file, an attacker can trigger an out-of-bounds memory read when hivex parses registry values containing malformed large data block lists. This issue can cause the application processing the registry file to crash, resulting in a Denial of Service (DoS).
Vulnerability Analysis
CVE-2026-120740 is exploitable with network access, requires user interaction and user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
Out-of-bounds Read
The software reads data past the end, or before the beginning, of the intended buffer. Typically, this can allow attackers to read sensitive information from other memory locations or cause a crash. A crash can occur when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string. The expected sentinel might not be located in the out-of-bounds memory, causing excessive data to be read, leading to a segmentation fault or a buffer overflow. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent read operation then produces undefined or unexpected results.
Products Associated with CVE-2026-120740
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