{"id":"CVE-2026-55738","aliases":["EUVD-2026-37712","GHSA-7fm7-h87x-9hjq"],"status":"published","title":"Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field","description":"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.","severity":{"version":"4.0","score":8.7,"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00398,"percentile":0.34378,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-121","CWE-170"],"published":"2026-06-17T13:45:00Z","modified":"2026-10-28T02:30:35Z","products":[{"vendor":"rxi","product":"microtar"}],"references":[{"url":"https://github.com/rxi/microtar/blob/master/src/microtar.c#L111","tags":["product","web"]},{"url":"https://github.com/rxi/microtar","tags":["product","package"]},{"url":"https://raw.githubusercontent.com/rxi/microtar/master/src/microtar.c","tags":["technical-description","article"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55738","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-7fm7-h87x-9hjq"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55738.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-55738","title":"Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field","description":"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.","status":"published","published":"2026-06-17T13:45:00.399Z","modified":"2026-08-10T11:44:14.85Z","cvss":[{"version":"4.0","score":8.7,"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","level":"high","assessor":"cna"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-121","CWE-170"],"updated_at":"2026-11-02T14:20:11.925815Z"}],"euvd":[{"id":"EUVD-2026-37712","description":"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.","status":"published","published":"2026-06-17T13:45:00Z","modified":"2026-08-10T11:44:14Z","cvss":[{"version":"4.0","score":8.7,"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","level":"high"}],"updated_at":"2026-11-02T18:02:06.086083Z"}],"ghsa":[{"id":"GHSA-7fm7-h87x-9hjq","title":"A stack-based buffer overflow exists in the raw_to_header() function in src/microtar.c in rxi...","description":"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.","status":"published","published":"2026-06-17T18:35:55Z","modified":"2026-06-17T18:36:01Z","cvss":[{"version":"4.0","score":8.7,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-121"],"updated_at":"2026-11-02T15:08:52.409657Z"}],"nvd":[{"id":"CVE-2026-55738","description":"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.","status":"published","published":"2026-06-17T14:18:00.057Z","modified":"2026-10-26T12:10:00.13Z","cvss":[{"version":"4.0","score":8.7,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-121","CWE-170"],"updated_at":"2026-11-02T14:12:24.544761Z"}],"osv":[{"id":"CVE-2026-55738","title":"Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field","description":"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.","status":"published","published":"2026-06-17T13:45:00.399Z","modified":"2026-10-28T02:30:35.811371579Z","cvss":[{"version":"4.0","score":8.7,"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","level":"high"}],"cwes":["CWE-121","CWE-170"],"updated_at":"2026-11-02T15:45:11.22012Z"}]}}