CVE-2026-115923

Backstage is an open framework for building developer portals. Prior to 3.9.2 and from 4.0.0 until 4.0.2, DefaultCatalogRulesEnforcer in @backstage/plugin-catalog-backend compares the raw location.target URL against catalog.rules, while URL readers canonicalize the same URL before fetching it. An authenticated user with catalog.location.create permission can use percent-encoded path segments to make an untrusted URL match a trusted location pattern even though the canonical URL resolves outside that scope. This admits entity content from an untrusted source as trusted, while further downstream consequences depend on deployment configuration. This issue is fixed in versions 3.9.2 and 4.0.2.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/backstage/backstage/commit/3214dc8f15d4a08a2fd07a72a8fe4d00aeac0db4
https://github.com/backstage/backstage/commit/737ff1c719dbd5a97f375b7f1db6d61416618419
https://github.com/backstage/backstage/releases/tag/v1.54.10
https://github.com/backstage/backstage/releases/tag/v1.56.1
https://github.com/backstage/backstage/security/advisories/GHSA-w658-mh9p-ww8f

Configurations

No configuration.

History

26 Oct 2026, 18:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-26 18:17

Updated : 2026-10-26 18:39

NVD link : CVE-2026-115923

Mitre link : CVE-2026-115923

CVE.ORG link : CVE-2026-115923

JSON object : View

Products Affected

No product.

CWE

CWE-22

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

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