Security readout for executives and security teams
Plain-English summary
RustFS alpha versions contain an IAM authorization flaw. A restricted service account or temporary credential may create a new service account without the intended restrictions, effectively regaining the parent account’s full privileges. This can undermine least-privilege controls in RustFS deployments.
Executive priority
Treat as a timely remediation item where RustFS alpha builds protect sensitive data or administrative workflows. It is not reported as actively exploited, but it can defeat access restrictions and allow privilege expansion inside affected RustFS environments.
Technical view
CVE-2026-22043 affects RustFS 1.0.0-alpha.13 through before 1.0.0-alpha.79. A flawed IAM `deny_only` short-circuit allows restricted service account or STS credentials to mint an unrestricted service account. The issue is classified under CWE-269 and CWE-284, with CVSS 4.0 score 5.7.
Likely exposure
Exposure is limited to organizations running affected RustFS alpha versions and using IAM service accounts or STS credentials with restrictive session or inline policies. Systems not using RustFS, or already on 1.0.0-alpha.79 or later, are not indicated as affected by the provided sources.
Exploitation context
The CVE record does not indicate CISA KEV listing or active exploitation. Exploitation requires low privileges and network access, with no user interaction. The impact described is privilege escalation through bypassing intended IAM restrictions, primarily affecting integrity of access control decisions.
Researcher notes
The public description identifies the root cause as a `deny_only` IAM short-circuit. Available sources name the fixed version but do not provide deeper implementation detail in the supplied bundle. Avoid assuming exploit maturity beyond the CVSS exploitability indicator and advisory description.
Mitigation direction
- Upgrade RustFS to version 1.0.0-alpha.79 or later.
- Review RustFS vendor advisory for any additional guidance.
- Audit restricted service accounts and STS credential usage in affected deployments.
- Rotate credentials created by restricted accounts during the exposure window if warranted.
Validation and detection
- Inventory RustFS versions across environments.
- Confirm whether any instance runs 1.0.0-alpha.13 through 1.0.0-alpha.78.
- Review IAM configurations using service accounts or STS credentials.
- Check for service accounts created by restricted principals before remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-269: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-22043 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.7 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
5.7MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/rustfs/rustfs/security/advisories/GHSA-xgr5-qc6w-vcg9CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Privilege Management
Improper Privilege Management represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.