CVE-2026-106491Backstage: Improper input validation in proxy-backend
Updated under an hour ago ()
Does this affect you?
It affects backstage and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
Backstage is an open framework for building developer portals. Prior to 0.6.17, the @backstage/plugin-proxy-backend package is affected by improper input validation in proxy-backend. An authenticated Backstage user could craft a request URL that causes the proxy-backend to forward the request to a path outside the configured base path on the target server. This is limited to target servers already configured as proxy endpoints and requires Backstage authentication by default. This issue is fixed in version 0.6.17.
- CVSS
- 6.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- Weakness (CWE)
- CWE-20, CWE-22
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Undergoing Analysis
- Record last updated
- Oct 7, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
backstage backstage backstage:backstage (from the name) | before 1.54.6 | CNA record |
@backstage plugin-proxy-backend backstage:plugin_proxy_backend (from the name) | before 0.6.17 | CNA record |
References
- https://github.com/backstage/backstage/security/advisories/GHSA-9ghw-48h5-v2w5x-refsource-confirm
- https://github.com/backstage/backstage/commit/233287d0ce3133e41549bf92a7470c940a41753cx-refsource-misc
- https://github.com/backstage/backstage/releases/tag/v1.54.6x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.