RustFS: ListRemoteTargetHandler authorization bypass leaks replication target credentials

published 2026-06-26 4 mo ago modified 2026-06-27 4 mo ago also EUVD-2026-39866

cvss: 8.2; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

RustFS is a distributed object storage system built in Rust. From 1.0.0-alpha.1 until 1.0.0-beta.9, RustFS contains an authorization bypass in the bucket replication admin API. The ListRemoteTargetHandler handler for listing remote replication targets only checks whether request credentials exist, but does not verify that the caller has replication or administrator permissions. As a result, an authenticated user with no effective bucket or admin permissions can list remote replication target configuration for a bucket. Because the returned BucketTarget objects include remote target credentials, this can disclose replication access keys and secret keys. This vulnerability is fixed in 1.0.0-beta.9.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 4 mo ago (2026-06-27)

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/rustfs/rustfs/security/advisories/GHSA-796f-j7xp-hwf4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.2	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected products

rustfs rustfs

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-522 Insufficiently Protected Credentials
CWE-862 Missing Authorization
CWE-863 Incorrect Authorization

References

github.com /rustfs/rustfs/security/advisories/GHSA-796f-j7xp-hwf4
exploit

Sources

CVE List CVE-2026-55188
NVD CVE-2026-55188

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary