CVE-2026-39822

Root escape via symlink plus trailing slash in os

HIGH

7.8

CVSS Score

Published: July 8, 2026 at 03:46 PM UTC

Updated: October 25, 2026 at 05:10 PM UTC

2 products affected across 2 vendorsGoOS

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Severity

HIGH7.8

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Go · Golang

95%

1.24.0 ≤ v < 1.25.121.26.0 ≤ v < 1.26.51.27 1.27 rc1

Affected range stops below 1.25.12, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.26.5, so it looks safe — our inference, not a vendor statement

OS · Go Standard Librarygo

90%

v < 1.25.121.26.0-0 ≤ v < 1.26.51.27.0-0 ≤ v < 1.27.0-rc.21.26.0-0 1.27.0-0

Affected range stops below 1.25.12, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.26.5, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.27.0-rc.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (4)

Issue TrackingPatch

Source: cverecord

https://go.dev/issue/79005

Mailing ListPatchVendor Advisory

Source: cverecord

https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc

Patch

Source: cverecord

https://go.dev/cl/797880

Vendor Advisory

Source: cverecord

https://pkg.go.dev/vuln/GO-2026-4970

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHCISA-ADP

Attack Vector: LOCAL
Complexity: LOW
Privileges: LOW
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusANALYZED

CWE

CWE-61

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