CVE-2026-22043 [Medium] | Privilege Escalation in Rustfs

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.

EDB-ID	Source	Kind	Published	Link
—	nvd_ref	exploit_tag		Exploit-DB ↗

EDB-ID

Source

Kind

Published

Link

—

nvd_ref

exploit_tag

Exploit-DB ↗

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-02-18	0.06%	0.02%	-0.04%
2	2026-02-09	0.04%	0.06%	+0.02%
3	2026-01-09	—	0.04%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-02-18

0.06%

0.02%

-0.04%

2026-02-09

0.04%

0.06%

+0.02%

2026-01-09

—

0.04%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.7	4.0	MEDIUM	`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/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` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network. Attack complexity (AC:L) Exploitation conditions are straightforward and stable. Attack requirements (AT:N) No additional preconditions are required beyond normal reachability. Privileges required (PR:L) Low privileges are required. User interaction (UI:N) No user interaction is required. Vulnerable system confidentiality impact (VC:N) No confidentiality impact on the vulnerable system. Vulnerable system integrity impact (VI:H) High integrity impact on the vulnerable system. Vulnerable system availability impact (VA:N) No availability impact on the vulnerable system. Subsequent system confidentiality impact (SC:N) No confidentiality impact on subsequent systems. Subsequent system integrity impact (SI:N) No integrity impact on subsequent systems. Subsequent system availability impact (SA:N) No availability impact on subsequent systems. Exploit maturity (threat) (E:P) Proof-of-concept: public PoC exists; no reported exploitation and no known simplification tools. Confidentiality requirement (CR:X) Not defined: insufficient information; scoring treats this like High (worst case). Integrity requirement (IR:X) Not defined: insufficient information; scoring treats this like High (worst case). Availability requirement (AR:X) Not defined: insufficient information; scoring treats this like High (worst case). Modified attack vector (MAV:X) Not defined: scoring uses the Base Attack Vector (AV). Modified attack complexity (MAC:X) Not defined: scoring uses the Base Attack Complexity (AC). Modified attack requirements (MAT:X) Not defined: scoring uses the Base Attack Requirements (AT). Modified privileges required (MPR:X) Not defined: scoring uses the Base Privileges Required (PR). Modified user interaction (MUI:X) Not defined: scoring uses the Base User Interaction (UI). Modified vulnerable system confidentiality impact (MVC:X) Not defined: scoring uses the Base VC metric. Modified vulnerable system integrity impact (MVI:X) Not defined: scoring uses the Base VI metric. Modified vulnerable system availability impact (MVA:X) Not defined: scoring uses the Base VA metric. Modified subsequent system confidentiality impact (MSC:X) Not defined: scoring uses the Base SC metric. Modified subsequent system integrity impact (MSI:X) Not defined: scoring uses the Base SI metric. Modified subsequent system availability impact (MSA:X) Not defined: scoring uses the Base SA metric. Safety (supplemental) (S:X) Not evaluated. Automatable (supplemental) (AU:X) Not evaluated. Recovery (supplemental) (R:X) Not evaluated. Value density (supplemental) (V:X) Not evaluated. Vulnerability response effort (supplemental) (RE:X) Not evaluated. Provider urgency (supplemental) (U:X) Not evaluated.	—	—	[email protected]
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.7

4.0

MEDIUM

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/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

Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L): Exploitation conditions are straightforward and stable.
Attack requirements (AT:N): No additional preconditions are required beyond normal reachability.
Privileges required (PR:L): Low privileges are required.
User interaction (UI:N): No user interaction is required.
Vulnerable system confidentiality impact (VC:N): No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H): High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N): No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N): No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N): No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N): No availability impact on subsequent systems.
Exploit maturity (threat) (E:P): Proof-of-concept: public PoC exists; no reported exploitation and no known simplification tools.
Confidentiality requirement (CR:X): Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X): Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X): Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X): Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X): Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X): Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X): Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X): Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X): Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X): Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X): Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X): Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X): Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X): Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X): Not evaluated.
Automatable (supplemental) (AU:X): Not evaluated.
Recovery (supplemental) (R:X): Not evaluated.
Value density (supplemental) (V:X): Not evaluated.
Vulnerability response effort (supplemental) (RE:X): Not evaluated.
Provider urgency (supplemental) (U:X): Not evaluated.

—

[email protected]

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

Weakness enumeration for CVE-2026-22043

Affected software / configurations for CVE-2026-22043

Vendor	Product	Version	Raw CPE
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha13::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha14::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha15::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha16::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha17::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha18::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha19::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha20::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha21::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha22::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha23::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha24::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha25::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha26::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha27::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha28::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha29::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha30::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha31::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha32::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha33::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha34::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha35::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha36::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha37::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha38::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha39::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha40::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha41::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha42::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha43::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha44::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha45::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha46::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha47::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha48::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha49::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha50::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha51::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha52::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha53::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha54::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha55::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha56::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha57::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha58::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha59::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha60::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha61::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha62::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha63::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha64::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha65::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha66::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha67::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha68::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha69::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha70::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha71::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha72::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha73::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha74::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha75::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha76::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha77::::rust::*
rustfs	rustfs	1.0.0	cpe:2.3:a:rustfs:rustfs:1.0.0:alpha78::::rust::*

References for CVE-2026-22043

URL	Tags
https://github.com/rustfs/rustfs/security/advisories/GHSA-xgr5-qc6w-vcg9	Exploit Vendor Advisory

URL

CVE-2026-22043 | RustFS has IAM deny_only Short-Circuit that Allows Privilege Escalation via Service Account Minting

Public exploit references (Exploit-DB) for CVE-2026-22043

Exploit prediction scoring system (EPSS) score for CVE-2026-22043

Common vulnerability scoring system (CVSS) metrics for CVE-2026-22043

Weakness enumeration for CVE-2026-22043

GitHub Security Advisory for CVE-2026-22043

Affected software / configurations for CVE-2026-22043

References for CVE-2026-22043