Arbitrary symlink creation via unchecked archive target
Published Jul 9, 2026 · Updated Jul 9, 2026
Improper symlink handling in decompress before 4.2.2 allows remote attackers to plant arbitrary links through crafted archives. The symlink branch passes an archive entry's x.linkname directly to fs.symlink(), while output-boundary validation covers only ordinary file writes. Exploitation requires a consuming application to extract attacker-controlled content; the planted link can redirect later process access outside the output directory.
Summary
What happened
Improper symlink handling in decompress before 4.2.2 allows remote attackers to plant arbitrary links through crafted archives. The symlink branch passes an archive entry's x.linkname directly to fs.symlink(), while output-boundary validation covers only ordinary file writes. Exploitation requires a consuming application to extract attacker-controlled content; the planted link can redirect later process access outside the output directory.
The record
- CVE
- CVE-2026-39246
- Published
- Jul 9, 2026
- Updated
- Jul 9, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-59
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 9, 2026CVE publishedPublication date reported by the CVE source.
- Jul 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
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Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- Arbitrary symlink creation proof of conceptproof of concept · unverified
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Technologies
Your stack
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Your stack
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