CVE-2026-48100

Payy is an Ethereum L2 zk-rollup for privacy preserving and regulatory compliant transactions. Prior to version 1.3.0, agg_agg forwards the compacted message stream from its inner proofs into a public messages: [Field; 1000] array, but it never checks that the unused tail of the outer array is zero. A registered prover can build a valid agg_final proof for an approved rollup block while inserting an extra burn message after the real messages. RollupV1.verifyRollup() then parses that public input as a normal burn and transfers USDC from the rollup contract to the attacker. This is a severe circuit soundness failure: the proof system accepts a public statement whose messages array is not fully derived from the verified inner proofs. On the current deployment, verifyRollup() is restricted to the existing allowlisted prover, so a fresh public caller cannot submit the invalid proof directly. That gate limits who can reach L1 today; it does not make the circuit statement sound. The issue becomes permissionless under the prover model described in the Payy whitepaper. Section 3.3.2 states: "To join as a prover, the prover is required to submit a small stake", and Section 3.3.1 states that if a prover fails to submit, "other nodes can submit the block proof instead." In that model, an attacker only needs to become a registered prover and use public validator approval data for an already approved block. This issue has been patched in version 1.3.0.
CVSS

No CVSS.

Configurations

No configuration.

History

28 Sep 2026, 18:17

Type Values Removed Values Added
References () https://github.com/polybase/payy/security/advisories/GHSA-fhxc-63vg-9gwr - () https://github.com/polybase/payy/security/advisories/GHSA-fhxc-63vg-9gwr -

28 Sep 2026, 17:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-09-28 17:17

Updated : 2026-09-30 19:57


NVD link : CVE-2026-48100

Mitre link : CVE-2026-48100

CVE.ORG link : CVE-2026-48100


JSON object : View

Products Affected

No product.

CWE
CWE-349

Acceptance of Extraneous Untrusted Data With Trusted Data