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High severityOSV Advisory· Published Jan 28, 2026· Updated Jan 28, 2026

node-tar Vulnerable to Arbitrary File Creation/Overwrite via Hardlink Path Traversal

CVE-2026-24842

Description

node-tar,a Tar for Node.js, contains a vulnerability in versions prior to 7.5.7 where the security check for hardlink entries uses different path resolution semantics than the actual hardlink creation logic. This mismatch allows an attacker to craft a malicious TAR archive that bypasses path traversal protections and creates hardlinks to arbitrary files outside the extraction directory. Version 7.5.7 contains a fix for the issue.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
tarnpm
< 7.5.77.5.7

Affected products

1

Patches

1
f4a7aa9bc3d7

fix: properly sanitize hard links containing ..

https://github.com/isaacs/node-tarisaacsJan 27, 2026via ghsa
commit
2 files changed · +22 −1
  • src/unpack.ts+2 −1 modified
    @@ -271,6 +271,7 @@ export class Unpack extends Parser {
     field: 'path' | 'linkpath',
   ): boolean {
     const p = entry[field]
+    const { type } = entry
     if (!p || this.preservePaths) return true
 
     const parts = p.split('/')
@@ -284,7 +285,7 @@ export class Unpack extends Parser {
       // just rejecting any path with '..' - relative symlinks like
       // '../sibling/file' are valid if they resolve within the cwd.
       // For paths, they just simply may not ever use .. at all.
-      if (field === 'path') {
+      if (field === 'path' || type === 'Link') {
         this.warn('TAR_ENTRY_ERROR', `${field} contains '..'`, {
           entry,
           [field]: p,
  • test/ghsa-8qq5-rm4j-mr97.ts+20 −0 modified
    @@ -23,6 +23,20 @@ const getExploitTar = () => {
   }).encode(hardHeader, 0)
   chunks.push(hardHeader)
 
+  const hardSubHeader = Buffer.alloc(1024)
+  new Header({
+    path: 'sub/',
+    type: 'Directory',
+    size: 0,
+  }).encode(hardSubHeader, 0)
+  new Header({
+    path: 'sub/exploit_sub',
+    type: 'Link',
+    size: 0,
+    linkpath: '../secret.txt',
+  }).encode(hardSubHeader, 512)
+  chunks.push(hardSubHeader)
+
   const symHeader = Buffer.alloc(512)
   new Header({
     path: 'exploit_sym',
@@ -77,6 +91,12 @@ t.test('hardlink escape does not clobber target', async t => {
     readFileSync(resolve(dir, 'secret.txt'), 'utf8'),
     'ORIGINAL DATA',
   )
+
+  writeFileSync(resolve(out, 'sub/exploit_sub'), 'OVERWRITTEN SUB')
+  t.equal(
+    readFileSync(resolve(dir, 'secret.txt'), 'utf8'),
+    'ORIGINAL DATA',
+  )
 })
 
 t.test('symlink escapes are sanitized', async t => {

Vulnerability mechanics

Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

4

News mentions

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