GRUB2: UAF in normal command leads to DoS
CVE-2025-61663 Published on November 18, 2025
Grub2: missing unregister call for normal commands may lead to use-after-free
A vulnerability has been identified in the GRUB2 bootloader's normal command that poses an immediate Denial of Service (DoS) risk. This flaw is a Use-after-Free issue, caused because the normal command is not properly unregistered when the module is unloaded. An attacker who can execute this command can force the system to access memory locations that are no longer valid. Successful exploitation leads directly to system instability, which can result in a complete crash and halt system availability. Impact on the data integrity and confidentiality is also not discarded.
Vulnerability Analysis
CVE-2025-61663 can be exploited with local system access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be low. considered to have a small impact on confidentiality and integrity and availability.
Timeline
Reported to Red Hat.
Made public. 6 days later.
Weakness Type
What is a Dangling pointer Vulnerability?
The program dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid. When a program releases memory, but it maintains a pointer to that memory, then the memory might be re-allocated at a later time. If the original pointer is accessed to read or write data, then this could cause the program to read or modify data that is in use by a different function or process. Depending on how the newly-allocated memory is used, this could lead to a denial of service, information exposure, or code execution.
CVE-2025-61663 has been classified to as a Dangling pointer vulnerability or weakness.
Products Associated with CVE-2025-61663
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Affected Versions
GNU grub2:- Before and including 2.14 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.