cbcvebase.
CVE-2026-22043
published 2026-01-08

CVE-2026-22043: 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…

PriorityP261critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.38%
29.6th percentile
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

5 ranges
VendorProductVersion rangeFixed in
rustfsrustfs
rustfsrustfs
rustfsrustfs>= 0 < 1.0.0-alpha.981.0.0-alpha.98
rustfsrustfs0 – 0.0.2
rustfsrustfs>= 1.0.0-alpha.13 < 1.0.0-alpha.791.0.0-alpha.79

Detection & IOCsextracted from sources · hover to see the quote

  • Monitor RustFS deployments running versions 1.0.0-alpha.13 through 1.0.0-alpha.78 for anomalous service account creation activity, especially where the resulting account has broader permissions than the originating credential.
  • Alert on privilege escalation patterns where session/inline policy restrictions are bypassed — a newly issued service account inheriting parent's full privileges despite the parent being restricted is a strong indicator of exploitation.
  • ·The vulnerability exists specifically in the IAM deny_only short-circuit logic; patched in version 1.0.0-alpha.79. Environments not yet upgraded remain fully exposed.
  • ·A public exploit is reported to exist for this CVE, raising the urgency of detection and patching.

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv4.05.7MEDIUMCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
ghsa8.1HIGH
osv8.1HIGH
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