High 7.7Published Oct 7, 2026

CVE-2026-106557Backstage: Improper input validation in TechDocs Markdown extension configuration

Updated under an hour ago (Oct 28, 2026, 6:50 PM ET)

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It affects backstage and 1 other product. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.30%, higher than 21% of scored CVEs.

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Every CVE for backstage

Exploited in the last 30 days

Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later.

CVSS: 7.7 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Weakness (CWE): CWE-22, CWE-918
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.30% (percentile 21)
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Oct 7, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

backstage backstage backstage:backstage (from the name)	before 1.50.5; from 1.51.0-next.0, < 1.54.6	CNA record
@backstage plugin-techdocs-node backstage:plugin_techdocs_node (from the name)	before 1.14.6; from 1.15.0, < 1.15.4	CNA record

References

References

https://github.com/backstage/backstage/security/advisories/GHSA-f7v3-xhm6-w245	x-refsource-confirm
https://github.com/backstage/backstage/commit/017ace52d9b327ededc6704cf17799c875ae0f29	x-refsource-misc
https://github.com/backstage/backstage/commit/2d9de4ca117a529de4b6ed7dfb7aa507ca7b3f91	x-refsource-misc
https://github.com/backstage/backstage/releases/tag/v1.50.5	x-refsource-misc
https://github.com/backstage/backstage/releases/tag/v1.54.6	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.