CVE-2026-106557
Backstage: Improper input validation in TechDocs Markdown extension configuration
Description
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.
INFO
Published Date :
Oct. 7, 2026, 5:16 p.m.
Last Modified :
Oct. 8, 2026, 9:33 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-106557
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update @backstage/plugin-techdocs-node to version 1.14.6 or later.
- Update @backstage/plugin-techdocs-node to version 1.15.4 or later.
- Ensure pymdown-extensions is updated to 10.21.3 or later.
- Update mkdocs-techdocs-core to 1.7.0 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-106557.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-106557 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-106557
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-106557 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-106557 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 07, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-106557', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-07T17:47:07.050445Z'} -
New CVE Received by [email protected]
Oct. 07, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N Added CWE CWE-22 Added CWE CWE-918 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/106xxx/CVE-2026-106557.json">CVE-2026-106557</a> Added Reference https://github.com/backstage/backstage/commit/017ace52d9b327ededc6704cf17799c875ae0f29 Added Reference https://github.com/backstage/backstage/commit/2d9de4ca117a529de4b6ed7dfb7aa507ca7b3f91 Added Reference https://github.com/backstage/backstage/releases/tag/v1.50.5 Added Reference https://github.com/backstage/backstage/releases/tag/v1.54.6 Added Reference https://github.com/backstage/backstage/security/advisories/GHSA-f7v3-xhm6-w245