Arbitrary file write via unvalidated dirent names
Published May 11, 2026 · Updated May 11, 2026
Path traversal in cramfsck extraction in Nicolas Pitre cramfs-tools 2.0 through 2.1 allows local users to write files outside the output directory. During cramfsck -x, do_directory copies raw directory-entry names into extraction paths, and expand_fs opens those paths without rejecting slash or dot components. An attacker must supply a crafted cramfs image for local extraction; exploitation creates or overwrites files reachable with the caller's privileges.
Summary
What happened
Path traversal in cramfsck extraction in Nicolas Pitre cramfs-tools 2.0 through 2.1 allows local users to write files outside the output directory. During cramfsck -x, do_directory copies raw directory-entry names into extraction paths, and expand_fs opens those paths without rejecting slash or dot components. An attacker must supply a crafted cramfs image for local extraction; exploitation creates or overwrites files reachable with the caller's privileges.
The record
- CVE
- CVE-2026-8274
- Published
- May 11, 2026
- Updated
- May 11, 2026
- Vendor
- Nicolas Pitre
- Product
- cramfs-tools
- Classifications
- CWE-22
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 11, 2026CVE publishedPublication date reported by the CVE source.
- May 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.0
- Affected versionversion=2.1
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
- cramfsck crafted-dirent poc.shproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo