CVE-2026-73289 RustFS: ForAllValues/ForAnyValue negated string conditions are transposed, inverting IAM and bucket-policy decisions
RustFS incorrectly evaluates negated IAM policy conditions, allowing attackers to bypass access controls and gain unauthorized access to stored data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-73289?
CVE-2026-73289 is a high-severity authentication bypass vulnerability in rustfs, published on 12 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-beta.12, RustFS evaluates the ForAllValues: and ForAnyValue: set qualifiers with the negated string operators StringNotEquals, StringNotEqualsIgnoreCase, StringNotLike, ArnNotEquals, and ArnNotLike using each other's semantics because crates/policy/src/policy/function/string.rs negates the aggregate result after eval or eval_like instead of negating each request-value predicate before quantification. Partially overlapping policy and request value sets can therefore make an Allow condition grant access to an excluded principal or make a Deny guardrail fail, including policies based on jwt:groups and jwt:roles; absent keys also receive the opposite ForAllValues: and ForAnyValue: behavior. This issue is fixed in version 1.0.0-beta.12.
Weakness: CWE-863
Which versions are affected by CVE-2026-73289?
How do I fix CVE-2026-73289?
No fix has been published for CVE-2026-73289 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-73289 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73289 exists.
Sources
Also known as GHSA-v9cp-qfw9-9pfp.