CVE-2026-106558

Status: AnalyzedHigh (8.8)—

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.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base score: 8.8

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.47%
Percentile among all scored CVEs: 39
Score date: 10/17/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1210 Exploitation of Remote Serviceslateral movement85 %
Primary impactT1059 Command and Scripting Interpreterexecution80 %
Secondary impactT1078 Valid Accountsstealth · persistence · privilege escalation · initial access70 %

CWE-502 (deserialization insegura) con acceso remoto autenticado (AV:N, PR:L) permite instanciar objetos Python arbitrarios en el generador, logrando RCE. Riesgo crítico si se ejecuta con credenciales backend.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account Management Disable or Remove Feature or Program Application Developer Guidance Active Directory Configuration Vulnerability Scanning User Training

Affected technologies (2)

Linuxfoundation — Backstage Linuxfoundation — Backstage Plugin-techdocs-node

CWEs

CWE-502

References

Raw JSON (NVD)

Show

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