CVE-2026-22043
RustFS has IAM deny_only Short-Circuit that Allows Privilege Escalation via Service Account Minting
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
rustfsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
RustFS is a distributed object storage system built in Rust. In versions 1.0.0-alpha.13 through 1.0.0-alpha.78, a flawed deny_only short-circuit in RustFS IAM allows a restricted service account or STS credential to self-issue an unrestricted service account, inheriting the parent’s full privileges. This enables privilege escalation and bypass of session/inline policy restrictions. Version 1.0.0-alpha.79 fixes the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | rustfs | ≥ 1.0.0-alpha.13&&< 1.0.0-alpha.79 | 1.0.0-alpha.79 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rustfs. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update rustfs to 1.0.0-alpha.79 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-22043 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-22043 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-22043. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-22043 in your dependencies?
O3 detects CVE-2026-22043 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.