CVE-2026-115923

6.5 MEDIUM 0.3% exploit odds Fix listed Disclosure Web app

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. High risk of data tampering.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-10-23 20:21 UTC ReservedThe CVE id was reserved by its CNA
2026-10-26 18:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-11-02 18:18 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 6.5 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-10-26 18:17 UTC
Last modified: 2026-11-02 18:18 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-22 · Path traversal
Record status: Awaiting Analysis

Attack profile CVSS 3.1 · 6.5

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-115923.md and follow it. Check whether this project is affected by CVE-2026-115923. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

· More options · Status badge

Download Square Reddit

Fix and advisories

References

NVD record · CVE.org record