CVE-2026-39822: CWE-61: UNIX Symbolic Link (Symlink) Following in Go standard library os
On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root when the final path component of the a path is a symbolic link and the path ends in /. For example, 'root.Open("symlink/")' will open "symlink" even when "symlink" is a symbolic link pointing outside of the root.
AI Analysis
Technical Summary
On Unix systems, the Go standard library's os package has a vulnerability (CVE-2026-39822) where the os.Root function improperly follows symbolic links when the final path component is a symlink and the path ends with a '/'. This behavior allows opening files outside the intended root directory by following symlinks that point elsewhere. The affected versions include exactly 1.26.0-0, 1.27.0-0, all versions before 1.25.12, and versions from 1.26.0-0 up to but excluding 1.26.5. There is no CVSS score or vendor advisory indicating a patch or workaround. The vulnerability is categorized under CWE-61 (Improper Restriction of Symbolic Links).
Potential Impact
This vulnerability can lead to unauthorized file access outside the intended root directory when using os.Root on Unix systems, potentially exposing sensitive files or data. The impact depends on how the os package is used in applications and whether attackers can control or influence the symlink paths. No known exploits have been reported, so the real-world impact is currently unknown.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should carefully validate and sanitize paths and avoid relying solely on os.Root for security boundaries involving symbolic links. Monitor official Go project communications for updates on patches or workarounds.
CVE-2026-39822: CWE-61: UNIX Symbolic Link (Symlink) Following in Go standard library os
Description
On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root when the final path component of the a path is a symbolic link and the path ends in /. For example, 'root.Open("symlink/")' will open "symlink" even when "symlink" is a symbolic link pointing outside of the root.
CVSS v3.1
Score 7.8high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
On Unix systems, the Go standard library's os package has a vulnerability (CVE-2026-39822) where the os.Root function improperly follows symbolic links when the final path component is a symlink and the path ends with a '/'. This behavior allows opening files outside the intended root directory by following symlinks that point elsewhere. The affected versions include exactly 1.26.0-0, 1.27.0-0, all versions before 1.25.12, and versions from 1.26.0-0 up to but excluding 1.26.5. There is no CVSS score or vendor advisory indicating a patch or workaround. The vulnerability is categorized under CWE-61 (Improper Restriction of Symbolic Links).
Potential Impact
This vulnerability can lead to unauthorized file access outside the intended root directory when using os.Root on Unix systems, potentially exposing sensitive files or data. The impact depends on how the os package is used in applications and whether attackers can control or influence the symlink paths. No known exploits have been reported, so the real-world impact is currently unknown.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should carefully validate and sanitize paths and avoid relying solely on os.Root for security boundaries involving symbolic links. Monitor official Go project communications for updates on patches or workarounds.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Go
- Date Reserved
- 2026-04-07T18:13:03.527Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e7ad4c9d9e3dbe36a7d51
Added to database: 07/08/2026, 16:29:08 UTC
Last enriched: 07/08/2026, 16:44:38 UTC
Last updated: 08/22/2026, 22:52:13 UTC
Views: 149
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