File disclosure via recursive symlink dereferencing
Published Aug 10, 2026 · Updated Aug 10, 2026
Link following in composefs tar-rs 0.4.11 through 0.4.46 allows attackers to read files outside the source root via planted symlinks. The Builder::append_dir_all function recursively dereferences links without checking whether resolved targets remain beneath the supplied source directory, then stores target contents as regular archive files. Exploitation requires control of a directory archived by a process with broader filesystem read access, and the consequence is disclosure of any target-readable file.
Summary
What happened
Link following in composefs tar-rs 0.4.11 through 0.4.46 allows attackers to read files outside the source root via planted symlinks. The Builder::append_dir_all function recursively dereferences links without checking whether resolved targets remain beneath the supplied source directory, then stores target contents as regular archive files. Exploitation requires control of a directory archived by a process with broader filesystem read access, and the consequence is disclosure of any target-readable file.
The record
- CVE
- CVE-2026-70622
- Published
- Aug 10, 2026
- Updated
- Aug 10, 2026
- Vendor
- composefs
- Product
- tar-rs
- Classifications
- CWE-59, T1005
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 10, 2026CVE publishedPublication date reported by the CVE source.
- Aug 10, 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=0.4.11 <=0.4.46
What conditions does exploitation require?
What is affected?
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
- Researcher symlink-escape proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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