{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-55738", "assignerOrgId": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c", "state": "PUBLISHED", "assignerShortName": "TuranSec", "dateReserved": "2026-06-17T12:59:17.620Z", "datePublished": "2026-06-17T13:45:00.399Z", "dateUpdated": "2026-06-17T13:45:07.535Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c", "shortName": "TuranSec", "dateUpdated": "2026-06-17T13:45:07.535Z"}, "title": "Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-121", "description": "CWE-121 Stack-based Buffer Overflow", "type": "CWE"}]}, {"descriptions": [{"lang": "en", "cweId": "CWE-170", "description": "CWE-170 Improper Null Termination", "type": "CWE"}]}], "affected": [{"vendor": "rxi", "product": "microtar", "collectionURL": "https://github.com/rxi/microtar", "repo": "https://github.com/rxi/microtar", "programFiles": ["src/microtar.c"], "programRoutines": [{"name": "raw_to_header"}], "versions": [{"status": "affected", "version": "0.1.0", "versionType": "semver"}], "defaultStatus": "affected"}], "descriptions": [{"lang": "en", "value": "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.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>A stack-based buffer overflow exists in the <code>raw_to_header()</code> function in <code>src/microtar.c</code> in rxi microtar 0.1.0. The function copies the 100-byte <code>name</code> and <code>linkname</code> fields of a TAR header with <code>strcpy()</code> 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 <code>linkname</code> field (followed by the trailing padding of the 512-byte raw header) contains no null terminator causes <code>strcpy()</code> 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 <code>mtar_open()</code>, <code>mtar_read_header()</code>, or <code>mtar_find()</code>) 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 <code>raw_to_header</code> at <code>src/microtar.c:112</code>.</p>"}]}], "references": [{"url": "https://github.com/rxi/microtar/blob/master/src/microtar.c#L111", "tags": ["product"]}, {"url": "https://github.com/rxi/microtar", "tags": ["product"]}, {"url": "https://raw.githubusercontent.com/rxi/microtar/master/src/microtar.c", "name": "Vulnerable source code: src/microtar.c (raw_to_header)", "tags": ["technical-description"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 8.8, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "HIGH", "baseScore": 8.7, "vectorString": "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"}}], "credits": [{"lang": "en", "value": "Saidakbarxon Maxsudxonov", "type": "finder"}], "source": {"discovery": "EXTERNAL"}}}}

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