Vulnerability-Lookup

GHSA-7FM7-H87X-9HJQ

Vulnerability from github – Published: 2026-06-17 18:35 – Updated: 2026-06-17 18:35

Details

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.

Severity

8.8 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

8.7 (High)


                  
                    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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-55738"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-121"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-17T14:18:00Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-7fm7-h87x-9hjq",
  "modified": "2026-06-17T18:35:55Z",
  "published": "2026-06-17T18:35:55Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55738"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rxi/microtar"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rxi/microtar/blob/master/src/microtar.c#L111"
    },
    {
      "type": "WEB",
      "url": "https://raw.githubusercontent.com/rxi/microtar/master/src/microtar.c"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-55738 (GCVE-0-2026-55738)

Vulnerability from cvelistv5 – Published: 2026-06-17 13:45 – Updated: 2026-06-17 15:00

Title

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

Summary

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

8.7 (High)


                        
                          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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

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

Assigner

TuranSec

References

3 references

URL	Tags
https://github.com/rxi/microtar/blob/master/src/m…	product
https://github.com/rxi/microtar	product
https://raw.githubusercontent.com/rxi/microtar/ma…	technical-description

Impacted products

1 product

Vendor	Product	Version
rxi	microtar	Affected: 0.1.0 (semver)

Credits

Saidakbarxon Maxsudxonov

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55738",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-17T15:00:50.582378Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-17T15:00:58.607Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://github.com/rxi/microtar",
          "defaultStatus": "affected",
          "product": "microtar",
          "programFiles": [
            "src/microtar.c"
          ],
          "programRoutines": [
            {
              "name": "raw_to_header"
            }
          ],
          "repo": "https://github.com/rxi/microtar",
          "vendor": "rxi",
          "versions": [
            {
              "status": "affected",
              "version": "0.1.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Saidakbarxon Maxsudxonov"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eA stack-based buffer overflow exists in the \u003ccode\u003eraw_to_header()\u003c/code\u003e function in \u003ccode\u003esrc/microtar.c\u003c/code\u003e in rxi microtar 0.1.0. The function copies the 100-byte \u003ccode\u003ename\u003c/code\u003e and \u003ccode\u003elinkname\u003c/code\u003e fields of a TAR header with \u003ccode\u003estrcpy()\u003c/code\u003e 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 \u003ccode\u003elinkname\u003c/code\u003e field (followed by the trailing padding of the 512-byte raw header) contains no null terminator causes \u003ccode\u003estrcpy()\u003c/code\u003e 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 \u003ccode\u003emtar_open()\u003c/code\u003e, \u003ccode\u003emtar_read_header()\u003c/code\u003e, or \u003ccode\u003emtar_find()\u003c/code\u003e) 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 \u003ccode\u003eraw_to_header\u003c/code\u003e at \u003ccode\u003esrc/microtar.c:112\u003c/code\u003e.\u003c/p\u003e"
            }
          ],
          "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
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          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
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          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
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          "descriptions": [
            {
              "cweId": "CWE-121",
              "description": "CWE-121 Stack-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-170",
              "description": "CWE-170 Improper Null Termination",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-17T13:45:07.535Z",
        "orgId": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
        "shortName": "TuranSec"
      },
      "references": [
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/rxi/microtar/blob/master/src/microtar.c#L111"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/rxi/microtar"
        },
        {
          "name": "Vulnerable source code: src/microtar.c (raw_to_header)",
          "tags": [
            "technical-description"
          ],
          "url": "https://raw.githubusercontent.com/rxi/microtar/master/src/microtar.c"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Stack Buffer Overflow in rxi/microtar raw_to_header() via non-null-terminated TAR name field"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
    "assignerShortName": "TuranSec",
    "cveId": "CVE-2026-55738",
    "datePublished": "2026-06-17T13:45:00.399Z",
    "dateReserved": "2026-06-17T12:59:17.620Z",
    "dateUpdated": "2026-06-17T15:00:58.607Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-7FM7-H87X-9HJQ

CVE-2026-55738 (GCVE-0-2026-55738)

Tags

Sightings

Nomenclature