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CVE-2026-106558

Backstage: Improper validation of TechDocs MkDocs configuration

CVSS score

8.8

EPSS probability

%0.5

Risk score

0.0

Published

5 d ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Patch status has not yet been verified

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Impact on My Inventory

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Vulnerability description

DayBreach CVE AI Research

CVE-2026-106558 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.

Backstage 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.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-106558 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1backstagebackstage View
2backstageplugin-techdocs-node View
3npm@backstage/plugin-techdocs-node View
Total affected vendors: 2|Products: 3

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
8.8CVSS V3_1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVE CNA
8.8CVSS 3.x—Vector not publishedGitHub Advisory
8.8CVSS V31HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD
0.0CVSS 4.0—Vector not publishedGitHub Advisory

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-106558 is associated with the following CWEs:

CWE-502: Deserialization of Untrusted Data

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-106558 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsLow
UserGerekmiyor

Official Sources and Advisories

https://github.com/backstage/backstage/security/advisories/GHSA-qmw3-745m-w99gvendor-advisoryhttps://github.com/backstage/backstage/commit/32723a0fe4e12ed80535fc65d5331765c55aa91bvendor-advisoryhttps://github.com/backstage/backstage/commit/944edb51c8524d3664b18f2d57ba101b1c93b709vendor-advisoryhttps://github.com/backstage/backstage/commit/f18e9abcc6051491862b15e4fc60e69f8d52310cvendor-advisoryhttps://github.com/backstage/backstage/releases/tag/v1.50.7vendor-advisoryhttps://github.com/backstage/backstage/releases/tag/v1.54.9vendor-advisoryhttps://github.com/backstage/backstage/releases/tag/v1.55.2vendor-advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-106558vendor-advisoryhttps://github.com/advisories/GHSA-qmw3-745m-w99gvendor-advisory

CVSS Vector Radar Chart

8.8 / 10
Attack VectorNetworkComplexityLowPrivilegesLowUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityHigh

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow privileges
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)High

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

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backstage
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npm

Weakness Type (CWE & CAPEC)

CWE-502

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