LiveActive security incident?Get immediate response
CVE Record

CVE-2026-24046: Backstage has a Possible Symlink Path Traversal in Scaffolder Actions

Backstage is an open framework for building developer portals. Multiple Scaffolder actions and archive extraction utilities were vulnerable to symlink-based path traversal attacks. An attacker with access to create and execute Scaffolder templates could exploit symlinks to read arbitrary files via the `debug:log` action by creating a symlink pointing to sensitive files (e.g., `/etc/passwd`, configuration files, secrets); delete arbitrary files via the `fs:delete` action by creating symlinks pointing outside the workspace, and write files outside the workspace via archive extraction (tar/zip) containing malicious symlinks. This affects any Backstage deployment where users can create or execute Scaffolder templates. This vulnerability is fixed in `@backstage/backend-defaults` versions 0.12.2, 0.13.2, 0.14.1, and 0.15.0; `@backstage/plugin-scaffolder-backend` versions 2.2.2, 3.0.2, and 3.1.1; and `@backstage/plugin-scaffolder-node` versions 0.11.2 and 0.12.3. Users should upgrade to these versions or later. Some workarounds are available. Follow the recommendation in the Backstage Threat Model to limit access to creating and updating templates, restrict who can create and execute Scaffolder templates using the permissions framework, audit existing templates for symlink usage, and/or run Backstage in a containerized environment with limited filesystem access.

CriticalCVSS 9.1Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

Backstage Scaffolder could let an authorized template user abuse symlinks so actions or archive extraction access files outside the intended workspace. Business impact is exposure or modification of sensitive host files, depending on deployment permissions and filesystem isolation. The issue is critical, but the provided sources do not show active exploitation.

Executive priority

Treat this as urgent for Backstage environments that allow non-admin template creation or execution. Prioritize upgrade and access restriction because the vulnerability can cross workspace boundaries and affect confidentiality, integrity, and availability. Risk is lower only where Scaffolder is tightly governed and runtime filesystem access is constrained.

Technical view

Multiple Scaffolder actions and archive extraction utilities mishandled symlinks, enabling path traversal outside the workspace. Reported impacts include arbitrary file read through debug logging, file deletion through fs delete behavior, and out-of-workspace writes through tar or zip extraction. Affected packages include backend-defaults, plugin-scaffolder-backend, and plugin-scaffolder-node below fixed versions.

Likely exposure

Exposure is likely where Backstage is deployed with Scaffolder enabled and users can create or execute templates, especially if templates run with broad filesystem access or host-mounted secrets. Instances without template authoring or execution access for untrusted users are less exposed, but version validation is still required.

Exploitation context

The attack requires a user who can create and execute Scaffolder templates. KEV is false in the provided bundle, and no cited source states active exploitation. The practical risk depends on Scaffolder permissions, template governance, container boundaries, and what sensitive files are reachable from the Backstage runtime.

Researcher notes

The root issue is symlink traversal across Scaffolder actions and extraction utilities. The advisory names read, delete, and write impacts but requires template execution privileges. Avoid assuming unauthenticated exposure. Validation should focus on package versions, permission framework policy, template governance, and filesystem isolation rather than probing file paths.

Mitigation direction

  • Upgrade affected Backstage packages to the listed fixed versions or later.
  • Restrict who can create, update, and execute Scaffolder templates.
  • Audit existing templates for symlink usage and unsafe archive handling.
  • Run Backstage with limited filesystem access in a containerized environment.
  • Review vendor guidance for any additional product-specific workarounds.

Validation and detection

  • Inventory Backstage package versions against the affected version ranges.
  • Confirm Scaffolder template creation and execution permissions are least-privilege.
  • Review templates and trusted archives for symlink-dependent behavior.
  • Check runtime mounts for secrets or host paths reachable by Backstage.
  • Verify fixed versions are deployed in all Backstage environments.
Prepared
Confidence
high
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-22: File access and web shell behavior lookup

File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cwe · low confidence lookup

CWE-59: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

File access behavior lookup

The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-24046 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.1 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
8Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.1CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L3.15.3redhat-SADP
7.1CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:L1.84.7GitHub_M

Vulnerability scoring details

Base CVSS 3.1 score

9.1Critical
CVSS 3.1 vector shape for CVE-2026-24046Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPbackstage/backend-defaults: backstage/plugin-scaffolder-backend: backstage/plugin-scaffolder-node: possible symlink path traversal in scaffolder actions
other:Red Hat severity ratingcvssV3_1
  • 2026-01-21T23:00:53.856Z: Reported to Red Hat.
  • 2026-01-21T22:36:30.794Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
backstagebackstage@backstage/backend-defaults < 0.12.2, @backstage/backend-defaults >= 0.13.0, < 0.13.2, @backstage/backend-defaults >= 0.14.0, < 0.14.1, @backstage/plugin-scaffolder-backend < 2.2.2, @backstage/plugin-scaffolder-backend >= 3.0.0, < 3.0.2, @backstage/plugin-scaffolder-backend >= 3.1.0, < 3.1.1, @backstage/plugin-scaffolder-node < 0.11.2, @backstage/plugin-scaffolder-node >= 0.12.0, < 0.12.3Listed
Weakness

CWE details

CWE-22CWE-59

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-22 · source CWE mapping

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-59 · source CWE mapping

Improper Link Resolution Before File Access ('Link Following')

Improper Link Resolution Before File Access ('Link Following') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs