Stack Buffer Overflow Vulnerability in microtar Affecting User Input

CVE-2026-71267

What is CVE-2026-71267?

The microtar library has a vulnerability in the mtar_write_file_header() and mtar_write_dir_header() functions, which are designed to write the headers for files and directories in a tar archive. These functions lack proper validation of user-supplied input, specifically failing to check if the length of the entry name exceeds the allocated 100-byte buffer. Consequently, when provided with a filename longer than 99 characters, a stack buffer overflow occurs, potentially allowing an attacker to overwrite adjacent memory, leading to unpredictable behavior or exploitation of the affected application.

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