How severe is CVE-2026-106509?

CVE-2026-106509 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.

Is CVE-2026-106509 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-106509?

CVE-2026-106509 primarily affects Linuxfoundation Backstage Plugin-techdocs-node. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-106509?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-106509 published?

CVE-2026-106509 was published on 2026-10-06 and last updated on 2026-10-09.

CVE-2026-106509

CVE-2026-106509 is a high-severity vulnerability in Linuxfoundation Backstage Plugin-techdocs-node with a CVSS 3.x base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.

Key facts

Severity: High (CVSS 3.x base score 7.7)
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Linuxfoundation Backstage Plugin-techdocs-node
Published: 2026-10-06
Last modified: 2026-10-09

Description

Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in mkdocs.yml that cause arbitrary code execution during the documentation build process. This issue is fixed in versions 1.14.6 and 1.15.4.

Frequently asked questions

What is CVE-2026-106509?: Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in mkdocs.yml that cause arbitrary code execution during the documentation build process. This issue is fixed in versions 1.14.6 and 1.15.4.
How severe is CVE-2026-106509?: CVE-2026-106509 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.
Is CVE-2026-106509 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-106509?: CVE-2026-106509 primarily affects Linuxfoundation Backstage Plugin-techdocs-node. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-106509?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-106509 published?: CVE-2026-106509 was published on 2026-10-06 and last updated on 2026-10-09.

References

Affected products (7)

cpe:2.3:a:linuxfoundation:backstage_plugin-techdocs-node:*:*:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:-:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:next0:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:next1:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:next2:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:next3:*:*:*:*:*:*

More vulnerabilities in Linuxfoundation Backstage Plugin-techdocs-node

CVE-2026-106558 — High (CVSS 8.8): Backstage is an open framework for building developer portals. Prior to 1.14.8, 1.15.6, and 2.0.1, the…
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CVE-2026-106505 — High (CVSS 7.7): Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the…
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