Backstage: Improper validation of TechDocs MkDocs configuration

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-106558
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-07 15:17:15 UTC
Updated2026-10-07 15:52:18 UTC
DescriptionBackstage is an open framework for building developer portals. Prior to 1.14.8, 1.15.6, and 2.0.1, the @backstage/plugin-techdocs-node package improperly validated mapping-style markdown_extensions configuration. An authenticated attacker who can register or influence an SCM-backed documentation source may bypass TechDocs sanitization and cause Python objects to be imported and instantiated in the generator runtime, leading to arbitrary code execution. Earlier fixes in versions 1.14.6 and 1.15.4 did not fully address the supported mapping representation of markdown_extensions. Impact is greatest when documentation generation runs with backend credentials, filesystem access, or internal network access. This issue is fixed in versions 1.14.8, 1.15.6, and 2.0.1.

Risk And Classification

Primary CVSS: v3.1 8.8 HIGH from [email protected]

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

Problem Types: CWE-502 | CWE-502 CWE-502: Deserialization of Untrusted Data

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Backstage Backstage affected < 1.50.7 Not specified
CNA Backstage Backstage affected >= 1.51.0-next.0, < 1.54.9 Not specified
CNA Backstage Backstage affected >= 1.55.0-next.0, < 1.55.2 Not specified
CNA @backstage Plugin-techdocs-node affected < 1.14.8 Not specified
CNA @backstage Plugin-techdocs-node affected >= 1.15.0, < 1.15.6 Not specified
CNA @backstage Plugin-techdocs-node affected >= 2.0.0, < 2.0.1 Not specified

References

ReferenceSourceLinkTags
github.com/backstage/backstage/commit/f18e9abcc6051491862b15e4fc60e69f8d... [email protected] github.com
github.com/backstage/backstage/commit/32723a0fe4e12ed80535fc65d5331765c5... [email protected] github.com
github.com/backstage/backstage/releases/tag/v1.54.9 [email protected] github.com
github.com/backstage/backstage/commit/944edb51c8524d3664b18f2d57ba101b1c... [email protected] github.com
github.com/backstage/backstage/security/advisories/GHSA-qmw3-745m-w99g [email protected] github.com
github.com/backstage/backstage/releases/tag/v1.50.7 [email protected] github.com
github.com/backstage/backstage/releases/tag/v1.55.2 [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© 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