SeaweedFS EUVD-2026-56156

Exploitation requires network reachability to the filer's gRPC port AND a filer running with a credential manager while jwt.filer_signing.key is left unset in security.toml - this unset key is the default state, so no attacker-supplied credentials or user interaction are needed against a default deployment. The concrete limiting factors are: the attacker must be able to reach the filer gRPC listener (frequently an internal-only port, so internet exposure is not guaranteed), the version must be prior to 4.24, and deployments that already configured jwt.filer_signing.key mount an authenticated service and are not exploitable. In short: no authentication or special privileges are required, but reachability of the gRPC port and the default/unset signing-key configuration are the gating conditions.

The signals align strongly toward high priority: the CVSS 3.1 vector AV:N/AC:L/PR:N/UI:N/C:H/I:H/A:H (9.8) indicates a network-reachable, low-complexity, unauthenticated flaw with full confidentiality, integrity, and availability impact, and the outcome - self-minted S3 admin credentials - makes technical impact total and the attack trivially automatable once the gRPC port is reachable. The main mitigating reality is exposure scope: the filer gRPC port is often bound to internal networks rather than the public internet, so real-world exploitability hinges on whether that port is reachable by an attacker, and any operator running the default configuration with an unset signing key on a reachable filer should treat this as urgent. No KEV listing and no public POC were identified, so there is no evidence of active exploitation yet; however, the public fix commit clearly reveals the vulnerable code path, which lowers the bar for exploit development. Note the config nuance: CVSS shows PR:N, but exploitation depends on the deployment leaving jwt.filer_signing.key unset - this is the insecure default, so PR:N is defensible, but a hardened deployment that already set the key is not exposed.

An attacker with network reach to the filer's gRPC port - for example a foothold on an adjacent host, a container in the same cluster network, or an exposed port - connects to the SeaweedIdentityAccessManagement service without any credentials. Given AV:N/AC:L/PR:N, they call CreateUser and CreateAccessKey to mint an S3 administrator access key, then use it to read, modify, or destroy all stored objects. No public exploit code has been identified, but the RPCs are standard gRPC calls and the fix commit documents the exact vulnerable methods.