rxi microtar 0.1.0 Archive src/microtar.c raw_to_header linkname stack-based overflow

Summaryinfo

A vulnerability described as critical has been identified in rxi microtar 0.1.0. Affected by this vulnerability is the function raw_to_header of the file src/microtar.c of the component Archive Handler. Such manipulation of the argument linkname leads to stack-based overflow. This vulnerability is referenced as CVE-2026-55738. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in rxi microtar 0.1.0 and classified as critical. Affected by this issue is the function raw_to_header of the file src/microtar.c of the component Archive Handler. The manipulation of the argument linkname with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is confidentiality, integrity, and availability. CVE summarizes:

A stack-based buffer overflow exists in the raw_to_header() function in src/microtar.c in rxi microtar 0.1.0. The function copies the 100-byte name and linkname fields of a TAR header with strcpy() without guaranteeing null termination of the source. The POSIX ustar format permits these fixed-width fields to be fully populated with non-null bytes, so a crafted archive whose linkname field (followed by the trailing padding of the 512-byte raw header) contains no null terminator causes strcpy() to read past the end of the 512-byte raw header stack buffer and to write past the destination header buffer. A remote attacker who supplies a crafted TAR archive that the victim opens or parses (via mtar_open(), mtar_read_header(), or mtar_find()) can cause an out-of-bounds read and a stack buffer overflow, resulting in denial of service (crash) and potentially arbitrary code execution. Confirmed with AddressSanitizer: stack-buffer-overflow READ of size 356 in raw_to_header at src/microtar.c:112.

The weakness was published by Saidakbarxon Maxsudxonov. The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-55738 since 06/17/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available.

Upgrading eliminates this vulnerability.

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Productinfo

Vendor

• rxi

Name

• microtar

Version

• 0.1.0

Website

• Product: https://github.com/rxi/microtar/

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