Permission changes outside root via symlink race
Published Apr 8, 2026 · Updated Apr 8, 2026
A TOCTOU race in Go internal/syscall/unix before 1.25.9 and 1.26.0-0 through 1.26.1 allows local users to change permissions outside an os.Root. Root.Chmod checks the path and then calls Linux fchmodat with AT_SYMLINK_NOFOLLOW, but that syscall ignores the flag, allowing a swapped symlink to redirect chmod beyond the root. Exploitation requires permission to replace the target with a symlink during the check-to-use window; the bounded effect is an unauthorized file-mode change.
Summary
What happened
A TOCTOU race in Go internal/syscall/unix before 1.25.9 and 1.26.0-0 through 1.26.1 allows local users to change permissions outside an os.Root. Root.Chmod checks the path and then calls Linux fchmodat with AT_SYMLINK_NOFOLLOW, but that syscall ignores the flag, allowing a swapped symlink to redirect chmod beyond the root. Exploitation requires permission to replace the target with a symlink during the check-to-use window; the bounded effect is an unauthorized file-mode change.
The record
- CVE
- CVE-2026-32282
- Published
- Apr 8, 2026
- Updated
- Apr 8, 2026
- Vendor
- Go
- Product
- internal/syscall/unix
- Classifications
- CWE-59, CWE-367, T1222.002
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 8, 2026CVE publishedPublication date reported by the CVE source.
- Apr 8, 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 <1.25.9
- Affected versionversion=1.26.0-0 <1.26.2
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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