Executive brief
The xmllint utility, a command-line tool included in the widely-used libxml2 library for XML processing, contains a memory leak in its interactive shell. When a user enters only whitespace, the program fails to release the allocated input buffer. An attacker or local user can repeatedly trigger this condition to exhaust system memory, causing the xmllint process to crash and creating a denial-of-service condition on the affected system.
Technical details
The vulnerability is a memory leak (CWE-772) in the interactive shell of xmllint. When user input consisting only of whitespace is submitted, the program skips command execution but fails to properly deallocate the memory buffer that was allocated to store the input. Repeated submissions of whitespace-only input cause memory to accumulate without being freed. The attack vector is local, requiring an attacker to have interactive access to the xmllint shell or the ability to automate whitespace submissions. Over time, this exhausts available system memory and terminates the xmllint process, resulting in a denial-of-service condition. A patch has been identified and should be available through libxml2 updates.
Affected products
- libxml2 Project libxml2 <UNKNOWN>
Timeline
- 2026-02-02: disclosed