Bug 2531549 (CVE-2026-88045)

Summary: CVE-2026-88045 github.com/rclone/rclone: rclone: Memory exhaustion leading to Denial of Service
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: aazores, cmah, eaguilar, ebaron, gparvin, jmatsuok, jtolenti, pjindal, rhaigner
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in rclone. A remote attacker can exploit a memory exhaustion vulnerability in the S3 streamed multipart path. By manipulating the `Content-Length` or `X-Amz-Decoded-Content-Length` headers, an attacker can cause the application to reserve excessive memory without sending the declared body. This can lead to the exhaustion of process or host memory, resulting in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-10 16:32:27 UTC 
rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.75.0 until 1.75.1, the serve S3 streamed multipart path in cmd/serve/s3/multipart.go passes attacker-controlled contentLength to multipart.NewRW().Reserve before reading request-body bytes. waitForTurn admits the current part and one oversized part when the buffer is empty despite --multipart-streaming-buffer-limit, and lib/pool allocates 1 MiB pages according to Content-Length or X-Amz-Decoded-Content-Length. A network client can retain or multiply these reservations without sending the declared body, exhausting process or host memory or permanently blocking request handlers. Anonymous S3 deployments require no credentials, while deployments using auth_key require an accepted S3 key. This issue is fixed in version 1.75.1.