Redis EUVD-2026-48762

Exploitation requires (1) an authenticated Redis session (PR:L) and (2) the ability to execute the RESTORE command with an attacker-supplied serialized payload - the description explicitly frames this as 'the unusual case where an authenticated attacker can execute RESTORE.' The payload must define a stream whose consumer-group PEL references the same NACK from more than one consumer, and the attacker must then trigger deletion/acknowledgement of both consumers (XGROUP DELCONSUMER / XACK) to cause the double free. Limiting factors: RESTORE is typically not granted to untrusted clients and can be blocked by ACLs; the vulnerability requires a valid authenticated connection (not remote-unauthenticated); and the high crafting precision plus specific stream/consumer-group state (reflected in AC:H) constrain reliable exploitation. Instances that isolate Redis to trusted single-tenant use, or that deny RESTORE via ACL, are effectively out of scope.

The provided CVSS 3.1 vector (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H, score 7.5) is internally consistent with the description: network-reachable but requiring an authenticated session (PR:L) and a hard-to-arrange precondition (AC:H) - the ability to execute RESTORE with attacker-controlled serialized data. EPSS is not provided in the input, so probabilistic exploitation likelihood cannot be quantified here. There is no CISA KEV listing, so exploitation is not confirmed in the wild; however, publicly available POC code (github.com/berabuddies/redis-poc) meaningfully raises practical risk. The critical gating factor is that RESTORE is not a default-exposed capability for untrusted users - the description itself calls this 'the unusual case where an authenticated attacker can execute RESTORE.' Real-world priority is therefore high for multi-tenant deployments or those where RESTORE is not restricted via ACLs, and considerably lower for single-tenant, network-isolated instances. The double-free yields heap corruption; full RCE is plausible but exploit reliability depends on allocator state and platform, which the input does not confirm.

An attacker with authenticated access to a multi-tenant or loosely-secured Redis instance (or who has compromised application credentials) issues a RESTORE command carrying a crafted stream payload whose consumer-group PEL shares a single NACK between two consumers. The attacker then issues XACK/XREADGROUP/DELCONSUMER operations to free the shared NACK twice, corrupting the heap and, given the publicly available POC, working toward arbitrary code execution in the redis-server process. The high attack complexity (AC:H) reflects the need for a valid RESTORE-capable session and a precisely crafted serialized payload.