CVE-2026-55738 PUBLISHED

Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field

Assigner: TuranSec
Reserved: 17.06.2026 Published: 17.06.2026 Updated: 17.06.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

Product Status

Vendor rxi
Product microtar
Versions Default: affected
  • Version 0.1.0 is affected

Credits

  • Saidakbarxon Maxsudxonov finder

References

Problem Types

  • CWE-121 Stack-based Buffer Overflow CWE
  • CWE-170 Improper Null Termination CWE