RustfsApplication
CVE-2026-21862
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedRustFS is a distributed object storage system built in Rust. Prior to version alpha.78, IP-based access control can be bypassed: get_condition_values trusts client-supplied X-Forwarded-For/X-Real-Ip without verifying a trusted proxy, so any reachable client can spoof aws:SourceIp and satisfy IP-allowlist policies. This issue has been patched in version alpha.78.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceRustFS versions prior to alpha.78 have an IP allowlist bypass vulnerability in the get_condition_values function. The system trusts client-supplied X-Forwarded-For and X-Real-Ip HTTP headers without verifying that the request was forwarded through a trusted reverse proxy, allowing any reachable attacker to spoof the aws:SourceIp condition and bypass IP-based access control policies.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
RustfsApplication
= 1.0.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify RustFS versionCheck the installed RustFS version using your package manager or cargo list rustfs. Compare the version against the affected range: versions prior to alpha.78.Affected if The installed version is earlier than alpha.78
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Determine if IP-based access control is in useReview your RustFS configuration for any policies or rules that reference aws:SourceIp condition or IP allowlisting functionality.Affected if IP-based access control policies using aws:SourceIp are configured
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Verify if reverse proxy headers are being processedInspect your RustFS or web server configuration to determine if X-Forwarded-For or X-Real-Ip headers from client requests are being read and trusted.Affected if The system processes X-Forwarded-For or X-Real-Ip headers from incoming requests without proxy verification
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Confirm reverse proxy is explicitly trustedCheck whether RustFS or the frontend web server is configured to only trust forwarded headers from known, specific proxy IP addresses.Affected if There is no explicit configuration specifying which reverse proxies are trusted before accepting forwarded headers
You are affected if you run RustFS version earlier than alpha.78, use IP-based access control policies, and do not verify that X-Forwarded-For/X-Real-Ip headers originate from a trusted reverse proxy.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to RustFS version alpha.78 or implement proper trusted proxy verification (e.g., validate the source IP against a configured list of trusted proxies before trusting forwarded headers).
alpha.78
- Upgrade Rustfs from version 1.0.0 to version alpha.78 or later to obtain the security patch
- After upgrading, verify that IP-based access controls are working correctly by testing with spoofed X-Forwarded-For/X-Real-Ip headers
- Ensure that any reverse proxy (e.g., nginx, HAProxy) is properly configured to set trusted proxy headers, and that Rustfs is configured to trust only that proxy for IP validation
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Rustfs
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-21862 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-21862 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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