CVE-2025-68926: RustFS has a gRPC Hardcoded Token Authentication Bypass

Should you act?

High exploit likelihood

EPSS ranks it in the top 5% of all CVEs for likely exploitation in the next 30 days. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 31.9%, percentile 98: FIRST’s model estimates a 31.9% chance of exploitation activity in the next 30 days, higher than 98% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes rustfs (crates.io (Rust)) >= 1.0.0-alpha.13, <= 1.0.0-alpha.77, fixed in 1.0.0-alpha.78. Check your lockfile, including transitive dependencies.

What it is

RustFS is a distributed object storage system built in Rust. In versions prior to 1.0.0-alpha.78, RustFS implements gRPC authentication using a hardcoded static token "rustfs rpc" that is publicly exposed in the source code repository, hardcoded on both client and server sides, non-configurable with no mechanism for token rotation, and universally valid across all RustFS deployments. Any attacker with network access to the gRPC port can authenticate using this publicly known token and execute privileged operations including data destruction, policy manipulation, and cluster configuration changes. Version 1.0.0-alpha.78 contains a fix for the issue.

From the GitHub advisory

Vulnerability Overview

Description

RustFS implements gRPC authentication using a hardcoded static token "rustfs rpc" that is: 1. Publicly exposed in the source code repository 2. Hardcoded on both client and server sides 3. Non-configurable with no mechanism for token rotation 4. Universally valid across all RustFS deployments

Any attacker with network access to the gRPC port can authenticate using this publicly known token and execute privileged operations including data destruction, policy manipulation, and cluster configuration changes.

CVSS 3.1 Score

Weakness type: CWE-798, CWE-287.

Product: rustfs (crates.io (Rust)) · Assigned by: GitHub_M · Published: 2025-12-30

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 31.85% probability of exploitation activity in the next 30 days; percentile 98.

Timeline

• 2025-12-30 — CVE record published by GitHub_M
• 2025-12-30 — GitHub-reviewed advisory GHSA-h956-rh7x-ppgj published (critical)
• 2026-01-05 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-h956-rh7x-ppgj github.com
2. CVE.org record CVE-2025-68926 cve.org
3. NVD entry CVE-2025-68926 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com

Critical crates.io (Rust) advisories · Today’s Security Digest