File overwrite via drive-relative symlink validation mismatch
Published Mar 9, 2026 · Updated Mar 9, 2026
Path traversal in tar before 7.5.11 allows attackers to overwrite files outside the extraction directory via a crafted archive. Unpack[STRIPABSOLUTEPATH] checks the original drive-relative linkpath for escape before stripping its drive prefix, then creates the symlink from the rewritten traversal path. Exploitation requires a process to extract an attacker-controlled tar archive and later write through the symlink, enabling file overwrite with that process's permissions.
Summary
What happened
Path traversal in tar before 7.5.11 allows attackers to overwrite files outside the extraction directory via a crafted archive. Unpack[STRIPABSOLUTEPATH] checks the original drive-relative linkpath for escape before stripping its drive prefix, then creates the symlink from the rewritten traversal path. Exploitation requires a process to extract an attacker-controlled tar archive and later write through the symlink, enabling file overwrite with that process's permissions.
The record
- CVE
- CVE-2026-31802
- Published
- Mar 9, 2026
- Updated
- Mar 9, 2026
- Vendor
- Isaac Z. Schlueter
- Product
- tar
- Classifications
- CWE-22
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 9, 2026CVE publishedPublication date reported by the CVE source.
- Mar 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 7.5.11
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- CVE-2026-31802 tar symlink traversal PoCproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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