Cleartext transmission of sensitive information in rclone - #VU137263
Published: July 9, 2026
Vulnerability identifier: #VU137263
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-319
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: rclone.org
Affected software:
rclone
rclone
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to cleartext transmission of sensitive information in the S3 backend redirect handling logic when following a same-host redirect from https to http. A remote attacker can cause a crafted redirect response to expose the AWS STS session token in cleartext to disclose sensitive information.
Exploitation requires use of temporary credentials that include an STS session token and a redirect that changes the scheme without changing the host and port.
Remediation
Install security update from vendor's website.