Sibling-directory file write via path-prefix bypass
Published Apr 7, 2026 · Updated Apr 7, 2026
Path traversal in pyLoad before 0.5.0b3.dev97 allows remote attackers to write files outside the extraction directory through a crafted tar archive. The UnTar _safe_extractall() check compares absolute-path strings with os.path.commonprefix(), so sibling paths sharing the extraction directory's character prefix pass and reach tar.extractall(). Exploitation requires a user to download and extract the archive with the ExtractArchive addon enabled; the demonstrated impact is writing or overwriting files in sibling directories.
Summary
What happened
Path traversal in pyLoad before 0.5.0b3.dev97 allows remote attackers to write files outside the extraction directory through a crafted tar archive. The UnTar _safe_extractall() check compares absolute-path strings with os.path.commonprefix(), so sibling paths sharing the extraction directory's character prefix pass and reach tar.extractall(). Exploitation requires a user to download and extract the archive with the ExtractArchive addon enabled; the demonstrated impact is writing or overwriting files in sibling directories.
The record
- CVE
- CVE-2026-35592
- Published
- Apr 7, 2026
- Updated
- Apr 7, 2026
- Vendor
- pyLoad
- Product
- pyLoad
- Classifications
- CWE-22, T1204.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 7, 2026CVE publishedPublication date reported by the CVE source.
- Apr 7, 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=< 0.5.0b3.dev97
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
- Self-contained tar path-prefix bypass proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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