Information disclosure in Rclone
CVE-2026-79780
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.
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.001 (3.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/rclone/rclone/security/advisories/GHSA-8mxv-9xhp-86h4 (vendor-advisory)
- www.vulncheck.com/advisories/rclone-before-credential-exposure-via-s3-redirect (third-party-advisory)
Frequently asked questions
- What is CVE-2026-79780?
- CVE-2026-79780 is a medium-severity vulnerability in Rclone, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-08-25.
- How severe is CVE-2026-79780?
- Medium severity. CVSS v3 base score is 5.3 out of 10.