Root escape via symlink plus trailing slash in os

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-39822
StatePUBLISHED
AssignerGo
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-08 17:17:21 UTC
Updated2026-07-13 14:54:26 UTC
DescriptionOn 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.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from ADP

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.001810000 probability, percentile 0.078110000 (date 2026-07-12)

Problem Types: CWE-61 | CWE-61: UNIX Symbolic Link (Symlink) Following | CWE-61 CWE-61 UNIX Symbolic Link (Symlink) Following

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Golang Go All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Go Standard Library Os affected 1.25.12 semver Not specified
CNA Go Standard Library Os affected 1.26.0-0 1.26.5 semver Not specified
CNA Go Standard Library Os affected 1.27.0-0 1.27.0-rc.2 semver Not specified

References

ReferenceSourceLinkTags
go.dev/cl/797880 [email protected] go.dev Patch
pkg.go.dev/vuln/GO-2026-4970 [email protected] pkg.go.dev Vendor Advisory
go.dev/issue/79005 [email protected] go.dev Issue Tracking, Patch
groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc [email protected] groups.google.com Mailing List, Patch, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Mundur (https://github.com/M0nd0R) (en)

© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report