rclone before v1.75.0 fails to sanitize IBM IAM bearer tokens and SSE-C encryption keys during S3 redirect callbacks, allowing credentials to be preserved across scheme or host changes. Attackers observing network traffic from a trusted endpoint can capture reusable IBM IAM tokens on same-host HTTPS-to-HTTP downgrades or SSE-C keys on cross-origin redirects to access protected S3 objects.
https://www.vulncheck.com/advisories/rclone-before-credential-exposure-via-s3-redirect
https://github.com/rclone/rclone/security/advisories/GHSA-8mxv-9xhp-86h4
Published: 2026-08-25
Updated: 2026-08-25
Base Score: 4.6
Vector: CVSS2#AV:A/AC:H/Au:N/C:C/I:N/A:N
Severity: Medium
Base Score: 5.3
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity: Medium
Base Score: 6
Vector: CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00095