FKIE_CVE-2026-23950

Vulnerability from fkie_nvd - Published: 2026-01-20 01:15 - Updated: 2026-01-20 01:15
Severity ?
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L
Summary
node-tar,a Tar for Node.js, has a race condition vulnerability in versions up to and including 7.5.3. This is due to an incomplete handling of Unicode path collisions in the `path-reservations` system. On case-insensitive or normalization-insensitive filesystems (such as macOS APFS, In which it has been tested), the library fails to lock colliding paths (e.g., `ß` and `ss`), allowing them to be processed in parallel. This bypasses the library's internal concurrency safeguards and permits Symlink Poisoning attacks via race conditions. The library uses a `PathReservations` system to ensure that metadata checks and file operations for the same path are serialized. This prevents race conditions where one entry might clobber another concurrently. This is a Race Condition which enables Arbitrary File Overwrite. This vulnerability affects users and systems using node-tar on macOS (APFS/HFS+). Because of using `NFD` Unicode normalization (in which `ß` and `ss` are different), conflicting paths do not have their order properly preserved under filesystems that ignore Unicode normalization (e.g., APFS (in which `ß` causes an inode collision with `ss`)). This enables an attacker to circumvent internal parallelization locks (`PathReservations`) using conflicting filenames within a malicious tar archive. The patch in version 7.5.4 updates `path-reservations.js` to use a normalization form that matches the target filesystem's behavior (e.g., `NFKD`), followed by first `toLocaleLowerCase('en')` and then `toLocaleUpperCase('en')`. As a workaround, users who cannot upgrade promptly, and who are programmatically using `node-tar` to extract arbitrary tarball data should filter out all `SymbolicLink` entries (as npm does) to defend against arbitrary file writes via this file system entry name collision issue.
References
security-advisories@github.comhttps://github.com/isaacs/node-tar/commit/3b1abfae650056edfabcbe0a0df5954d390521e6
security-advisories@github.comhttps://github.com/isaacs/node-tar/security/advisories/GHSA-r6q2-hw4h-h46w
Impacted products
Vendor Product Version
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "node-tar,a Tar for Node.js, has a race condition vulnerability in versions up to and including 7.5.3. This is due to an incomplete handling of Unicode path collisions in the `path-reservations` system. On case-insensitive or normalization-insensitive filesystems (such as macOS APFS, In which it has been tested), the library fails to lock colliding paths (e.g., `\u00df` and `ss`), allowing them to be processed in parallel. This bypasses the library\u0027s internal concurrency safeguards and permits Symlink Poisoning attacks via race conditions. The library uses a `PathReservations` system to ensure that metadata checks and file operations for the same path are serialized. This prevents race conditions where one entry might clobber another concurrently. This is a Race Condition which enables Arbitrary File Overwrite. This vulnerability affects users and systems using node-tar on macOS (APFS/HFS+). Because of using `NFD` Unicode normalization (in which `\u00df` and `ss` are different), conflicting paths do not have their order properly preserved under filesystems that ignore Unicode normalization (e.g., APFS (in which `\u00df` causes an inode collision with `ss`)). This enables an attacker to circumvent internal parallelization locks (`PathReservations`) using conflicting filenames within a malicious tar archive. The patch in version 7.5.4 updates `path-reservations.js` to use a normalization form that matches the target filesystem\u0027s behavior (e.g., `NFKD`), followed by first `toLocaleLowerCase(\u0027en\u0027)` and then `toLocaleUpperCase(\u0027en\u0027)`. As a workaround, users who cannot upgrade promptly, and who are programmatically using `node-tar` to extract arbitrary tarball data should filter out all `SymbolicLink` entries (as npm does) to defend against arbitrary file writes via this file system entry name collision issue."
    }
  ],
  "id": "CVE-2026-23950",
  "lastModified": "2026-01-20T01:15:57.870",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "LOW",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.3,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-01-20T01:15:57.870",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/isaacs/node-tar/commit/3b1abfae650056edfabcbe0a0df5954d390521e6"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/isaacs/node-tar/security/advisories/GHSA-r6q2-hw4h-h46w"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-176"
        },
        {
          "lang": "en",
          "value": "CWE-352"
        },
        {
          "lang": "en",
          "value": "CWE-367"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}


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