CVE-2026-106558 (GCVE-0-2026-106558)

Vulnerability from cvelistv5 – Published: 2026-10-07 14:45 – Updated: 2026-10-07 14:45
VLAI
Title
Backstage: Improper validation of TechDocs MkDocs configuration
Summary
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.
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-502 - Deserialization of Untrusted Data
Assigner
References
Impacted products
Vendor Product Version CPE status
backstage backstage Affected: < 1.50.7
Affected: >= 1.51.0-next.0, < 1.54.9
Affected: >= 1.55.0-next.0, < 1.55.2
guessed Create a notification for this product.
@backstage plugin-techdocs-node Affected: < 1.14.8
Affected: >= 1.15.0, < 1.15.6
Affected: >= 2.0.0, < 2.0.1
guessed Create a notification for this product.
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              "version": "\u003e= 1.55.0-next.0, \u003c 1.55.2"
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        }
      ],
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          "url": "https://github.com/backstage/backstage/releases/tag/v1.54.9"
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          "tags": [
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    "dateReserved": "2026-10-06T20:31:59.017Z",
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      "percentile": "0.3879"
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                "product": "backstage",
                "vendor": "backstage",
                "versions": [
                  {
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                    "version": "\u003c 1.50.7"
                  },
                  {
                    "status": "affected",
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                  },
                  {
                    "status": "affected",
                    "version": "\u003e= 1.55.0-next.0, \u003c 1.55.2"
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              },
              {
                "product": "plugin-techdocs-node",
                "vendor": "@backstage",
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                  },
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          }
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        "lastModified": "2026-10-07T15:52:18.453",
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}



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