Description
Gradio before version 6.15.0 contains a cookie injection vulnerability that allows remote attackers to perform cross-Space session fixation by exploiting a shared module-level HTTP client used across all users in the reverse proxy endpoint. Attackers controlling any HF Space can return a parent-domain cookie that the shared client stores and automatically replays into all subsequent proxy requests to other legitimate Spaces, affecting all users of the same Gradio deployment.
Affected products
gradio_project: gradio
References6
- github.com/gradio-app/gradio/commit/feb7237d01f359d2ad4ee42d003… Patch
- github.com/gradio-app/gradio/pull/13384 Issue TrackingPatch
- github.com/gradio-app/gradio/issues/13369 Issue Tracking
- github.com/gradio-app/gradio/releases/tag/gradio%406.15.0 ProductRelease Notes
- www.vulncheck.com/advisories/gradio-cookie-injection-via-shared… Broken Link
- github.com/gradio-app/gradio/issues/13369 Issue Tracking
Metrics
- CVSS 3.1
-
6.8
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - CVSS 4.0
-
7.6
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 29 · as of 14 November 2026
- CWE
- CWE-384
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.