How severe is CVE-2026-39360?

CVE-2026-39360 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-39360 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-39360?

CVE-2026-39360 primarily affects Rustfs. In total, 89 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-39360?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-39360 have an EU (EUVD) identifier?

Yes. CVE-2026-39360 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19867.

When was CVE-2026-39360 published?

CVE-2026-39360 was published on 2026-04-07 and last updated on 2026-06-17.

CVE-2026-39360

CVE-2026-39360 is a medium-severity vulnerability in Rustfs with a CVSS 3.x base score of 4.3. 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-862.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v4: 5.3
EPSS exploit prediction: 0% (10th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-19867
Weakness: CWE-862
Affected product: Rustfs
Published: 2026-04-07
Last modified: 2026-06-17

Description

RustFS is a distributed object storage system built in Rust. Prior to alpha.90, RustFS contains a missing authorization check in the multipart copy path (UploadPartCopy). A low-privileged user who cannot read objects from a victim bucket can still exfiltrate victim objects by copying them into an attacker-controlled multipart upload and completing the upload. This breaks tenant isolation in multi-user / multi-tenant deployments. This vulnerability is fixed in alpha.90.

Frequently asked questions

What is CVE-2026-39360?: RustFS is a distributed object storage system built in Rust. Prior to alpha.90, RustFS contains a missing authorization check in the multipart copy path (UploadPartCopy). A low-privileged user who cannot read objects from a victim bucket can still exfiltrate victim objects by copying them into an attacker-controlled multipart upload and completing the upload. This breaks tenant isolation in multi-user / multi-tenant deployments. This vulnerability is fixed in alpha.90.
How severe is CVE-2026-39360?: CVE-2026-39360 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-39360 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39360?: CVE-2026-39360 primarily affects Rustfs. In total, 89 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-39360?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-39360 have an EU (EUVD) identifier?: Yes. CVE-2026-39360 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19867.
When was CVE-2026-39360 published?: CVE-2026-39360 was published on 2026-04-07 and last updated on 2026-06-17.

References

https://github.com/rustfs/rustfs/security/advisories/GHSA-mx42-j6wv-px98

Affected products (89)

cpe:2.3:a:rustfs:rustfs:1.0.0:alpha1:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha10:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha11:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha12:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha13:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha14:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha15:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha16:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha17:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha18:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha19:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha2:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha20:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha21:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha22:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha23:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha24:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha25:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha26:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha27:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha28:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha29:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha3:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha30:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha31:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha32:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha33:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha34:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha35:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha36:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha37:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha38:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha39:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha4:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha40:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha41:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha42:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha43:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha44:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha45:*:*:*:rust:*:*

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