Vulnerability · Published May 28, 2026 · Assigned by GitHub_M

CVE-2026-45042RustFS: UploadPartCopy Does Not Enforce Destination Bucket Policy on Copy Source

High 7.1

In plain English

A high-severity incorrect authorization in rustfs from rustfs. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).

Severity (CVSS 4.0)7.1High

Exploit odds (30 days)0.2%top 89.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-beta.2, improper authorization in the UploadPartCopy operation allows copying objects across buckets without enforcing destination bucket restrictions on allowed copy sources. The implementation validates GetObject permission on the source bucket and PutObject on the destination bucket independently, but does not enforce any policy constraints on whether the destination bucket permits the specified copy source. This enables unauthorized cross-bucket data movement. This vulnerability is fixed in 1.0.0-beta.2.

Affected products (as reported)

Vendor	Product	Versions
rustfs	rustfs	< 1.0.0-beta.2

Weakness: CWE-863 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

References

https://github.com/rustfs/rustfs/security/advisories/GHSA-wfxj-ph3v-7mjf x_refsource_CONFIRM