AWS SDK for pandas EUVD-2026-112142

Exploitation requires that the victim uses awswrangler's Athena module (before 3.16.1) with the default query result location - i.e. no explicit result location is set and no workgroup result configuration is enforced - AND that the default Athena result bucket for the victim's account/region is not already owned by the victim, allowing an attacker to pre-create (squat) that S3 bucket in their own account. Exploitation is limited by UI:A (the victim must actively execute an Athena query through the SDK) and by the attack requirement that the bucket be unclaimed in that specific account/region combination; accounts that already own their default bucket, or that set an explicit s3_output or enforce a workgroup result configuration, are not exposed.

This is a moderate-severity, condition-dependent information-disclosure and tampering flaw, not an emergency. The vuln.today Decision label is 'this_month' (not act_now/emergency), and the CVSS 4.0 base score is 5.9. The 4.0 vector (AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:L/VA:N) shows the two factors that hold real risk down: AT:P signals a non-trivial attack requirement (the default Athena result bucket must not already be owned by the victim in that account/region, so an attacker can pre-create it), and UI:A requires the victim to actively run an Athena query through awswrangler's default result location. PR:N is accurate - the attacker needs their own AWS account to create an S3 bucket but no privilege on the victim's environment. Impact is asymmetric: VC:H (an attacker-owned bucket can expose the victim's query results) but only VI:L (result sets returned to the caller can be tampered). No CISA KEV listing is present and no EPSS score was supplied, so there is no signal of active or widespread exploitation; combined with AT:P this points to a targeted, opportunistic scenario (bucket name-squatting in unclaimed account/region combinations) rather than mass exploitation. No public exploit reference is present in the input. Priority is real for environments that rely on awswrangler's default Athena output location, but it is a configuration-and-ownership hygiene issue rather than a drop-everything bug.

An attacker pre-creates, in their own AWS account, an S3 bucket matching the default Athena query-result location name that a victim account would use in a given region but has not yet claimed. When the victim runs Athena queries through awswrangler (pre-3.16.1) without an explicit result location or enforced workgroup configuration, results are written to and read from the attacker-owned bucket, letting the attacker read those results and alter the result sets returned to the caller. No public exploit is identified in the provided sources.