CVE-2026-106558CWE-502insecure-deserialization

CVE-2026-106558

High · published October 7, 2026

CVSS v3.1
8.8
EPSS
0%
Percentile
39.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00469 · 39.6th percentile
Weakness
CWE-502 · Deserialization of Untrusted Data
Published
2026-10-07T19:17Z
Affected products (15)
ProductVersionsFixed in
linuxfoundation/backstage_plugin-techdocs-node< 1.14.81.14.8
linuxfoundation/backstage_plugin-techdocs-node≥ 1.15.0, < 1.15.61.15.6
linuxfoundation/backstage_plugin-techdocs-node≥ 2.0.0, < 2.0.12.0.1
linuxfoundation/backstage< 1.50.71.50.7
linuxfoundation/backstage≥ 1.51.1, < 1.54.81.54.8
linuxfoundation/backstage≥ 1.55.1, < 1.55.21.55.2
linuxfoundation/backstageall versions—
linuxfoundation/backstageall versions—
linuxfoundation/backstageall versions—
linuxfoundation/backstageall versions—
linuxfoundation/backstageall versions—
linuxfoundation/backstageall versions—
linuxfoundation/backstageall versions—
linuxfoundation/backstageall versions—
linuxfoundation/backstageall versions—
References (7)
EPSS history
Timeline
  • 09 OCT 03:26Z
    EPSS moved — → 0%
    epss
  • 07 OCT 14:45Z
    Backstage: Improper validation of TechDocs MkDocs configuration
    cvelistv5