CVE-2026-45042

CVE-2026-45042 is a high-severity vulnerability with a CVSS 4.0 base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

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.

Frequently asked questions

What is CVE-2026-45042?
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.
How severe is CVE-2026-45042?
CVE-2026-45042 has a CVSS 4.0 base score of 7.1, rated high severity.
Is CVE-2026-45042 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-45042?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-45042 have an EU (EUVD) identifier?
Yes. CVE-2026-45042 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32995.
When was CVE-2026-45042 published?
CVE-2026-45042 was published on 2026-05-28 and last updated on 2026-06-17.

References

Other CWE-863 (Incorrect Authorization) vulnerabilities

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