CVE-2026-106457

6.8 MEDIUM 0.4% exploit odds Fix listed Auth & access Web app

What it is

Backstage is an open framework for building developer portals. From 0.1.0 until 0.5.0, the @backstage/plugin-auth-backend-module-cloudflare-access-provider package is affected by insufficient audience validation in the cloudflare access auth provider. The Cloudflare Access auth provider verifies a token's signature and team issuer, but affected versions do not verify that the token was issued for the Backstage application. A user holding a valid token for another Access application in the same Cloudflare Zero Trust team may therefore be able to authenticate to Backstage if that token reaches the auth endpoint without the Backstage application's audience already being enforced upstream. Cloudflare Access normally evaluates the protected application before forwarding requests. This issue is fixed in version 0.5.0.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering.
Exploit odds: 0.4% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-10-06 16:49 UTC ReservedThe CVE id was reserved by its CNA
2026-10-06 21:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-27 20:48 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.4% in the next 30 days (EPSS).
Severity: 6.8 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-10-06 21:17 UTC
Last modified: 2026-10-27 20:48 UTC
Exploit probability: 0.4% · EPSS, next 30 days
Weakness: CWE-287 · Improper authentication
Record status: Analyzed

Affected

Linuxfoundation backstage\/plugin-auth-backend-module-cloudflare-access-provider < 0.5.0
Linuxfoundation Backstage < 1.55.0

Attack profile CVSS 3.1 · 6.8

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

Raw vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/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-2026-106457.md and follow it. Check whether this project is affected by CVE-2026-106457. 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