CyberSecBulletin
CVE-2026-55188NVD status: Deferred

rustfs: Exposure of Sensitive Information to an Unauthorized Actor

Published Updated By the CyberSecBulletin desk

CVE-2026-55188 is a high-severity exposure of sensitive information to an unauthorized actor vulnerability in rustfs, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected rustfs versions: >= 1.0.0-alpha.1, <= 1.0.0-beta.8. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of rustfs you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Rustfsrustfs>= 1.0.0-alpha.1, <= 1.0.0-beta.8Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N. Scored by CNA (github.com).

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

How developers prevent this class of flaw

  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities (CWE-200)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in rustfs

All rustfs vulnerabilities

Recent Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities

Spotted an error? Tell us.