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CVE-2026-106558

HIGH 8.8

Published 2026-10-07 · Last modified 2026-10-10

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.

ELEVATED IMPACT

Severe if exploited (CVSS 8.8), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.5%chance of exploitation in 30 days · 40th percentile

○ In CISA KEV ○ Catalogued PoC

Impact if exploited

8.8CVSS 3.1 · HIGH

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ⚠Privileges: Requires a low-privilege account
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

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Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot:

Affected

Vendors Backstage @Backstage Linuxfoundation

Products Backstage Plugin Techdocs Node Backstage Plugin Techdocs Node

Weakness (CWE)

  • CWE-502: : Deserialization of Untrusted Data

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References and research data (JSON)

Packages and version ranges

Each advisory describes its own package and affected ranges. A boundary applies to that range; it is not a universal upgrade recommendation.

  • @backstage/plugin-techdocs-node npm

    pkg:npm/%40backstage/plugin-techdocs-node

    SEMVER range
    • All earlier versions (introduced 0)
    • Fixed boundary (excluded): 1.15.4
    Additional upstream package constraints
    {
  "database": {
    "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-qmw3-745m-w99g/GHSA-qmw3-745m-w99g.json"
  }
}
    GitHub Advisory Database · GHSA-qmw3-745m-w99g · Updated 2026-10-07T18:15:12.165363848Z

Vendor product assessments

  • rhdh/rhdh-hub-rhel9 as a component of Red Hat Developer Hub · known affected

    Vendor assessment for this product only.

    pkg:oci/rhdh-hub-rhel9@sha256:6d6fb29bd26ff5f8ee2df1302cc228c1358a9dfde83f9609f0f6e24e8a6be7c4?repository_url=registry.redhat.io/rhdh/rhdh-hub-rhel9

    • workaround: Upstream workarounds for this issue include using external TechDocs generation in an isolated environment without sensitive credentials or host access, and restricting and reviewing changes to documentation configuration before generation. Limiting the ability to register or modify SCM-backed documentation sources to trusted users also reduces exposure. For the affected Red Hat products, a fix is being pursued by the responsible product teams and will be delivered through standard product update channels.
    • none available: Affected
    Red Hat · CVE-2026-106558 · Updated 2026-10-20T23:26:33+00:00
  • ansible-automation-platform/automation-portal as a component of Self-service automation portal 2 · known affected

    Vendor assessment for this product only.

    pkg:oci/automation-portal@sha256:ca5c8160a6cb0fa122c3cc91852325af72b9713db1c2683b68e91433b762e604?repository_url=registry.redhat.io/ansible-automation-platform/automation-portal

    • workaround: Upstream workarounds for this issue include using external TechDocs generation in an isolated environment without sensitive credentials or host access, and restricting and reviewing changes to documentation configuration before generation. Limiting the ability to register or modify SCM-backed documentation sources to trusted users also reduces exposure. For the affected Red Hat products, a fix is being pursued by the responsible product teams and will be delivered through standard product update channels.
    • none available: Affected
    Red Hat · CVE-2026-106558 · Updated 2026-10-20T23:26:33+00:00
  • ansible-automation-platform/bootc-automation-portal-rhel9 as a component of Self-service automation portal 2 · known affected

    Vendor assessment for this product only.

    pkg:oci/bootc-automation-portal-rhel9@sha256:58480702819796209b8cda6fe1b53ad78870575432da34ecfdc20cd446c8d81b?repository_url=registry.redhat.io/ansible-automation-platform/bootc-automation-portal-rhel9

    • workaround: Upstream workarounds for this issue include using external TechDocs generation in an isolated environment without sensitive credentials or host access, and restricting and reviewing changes to documentation configuration before generation. Limiting the ability to register or modify SCM-backed documentation sources to trusted users also reduces exposure. For the affected Red Hat products, a fix is being pursued by the responsible product teams and will be delivered through standard product update channels.
    • none available: Affected
    Red Hat · CVE-2026-106558 · Updated 2026-10-20T23:26:33+00:00

Known Affected Software Configurations

VendorProductVersion range
LinuxfoundationBackstage Plugin Techdocs Node< 1.14.8
LinuxfoundationBackstage Plugin Techdocs Node≥ 1.15.0 and < 1.15.6
LinuxfoundationBackstage Plugin Techdocs Node≥ 2.0.0 and < 2.0.1
LinuxfoundationBackstage< 1.50.7
LinuxfoundationBackstage≥ 1.51.1 and < 1.54.8
LinuxfoundationBackstage≥ 1.55.1 and < 1.55.2
LinuxfoundationBackstage1.51.0
LinuxfoundationBackstage1.51.0
LinuxfoundationBackstage1.51.0
LinuxfoundationBackstage1.51.0
LinuxfoundationBackstage1.51.0
LinuxfoundationBackstage1.55.0
LinuxfoundationBackstage1.55.0
LinuxfoundationBackstage1.55.0
LinuxfoundationBackstage1.55.0

All CVSS metrics

  • HIGH 8.8 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  • HIGH 8.8 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Patches & mitigations

Advisories

Technical & other

Sources: NVD · CVE.org · EPSS