Power of Attorney for Steve Gavel at Cabaletta Bio, Inc.

The filing is a Power of Attorney document for Steve Gavel, the Chief Commercial Officer of Cabaletta Bio, Inc. The document appoints Steven Nichtberger, M.D., Anup Marda, and Michael Gerard as attorneys-in-fact to execute Forms 3, 4, and 5 on behalf of Gavel in relation to his holdings and transactions in the company's securities. The Power of Attorney is effective from October 13, 2025, and remains in force until Gavel is no longer required to file these forms. The document also revokes all previous powers of attorney related to Gavel's obligations under Section 16(a) of the Securities Exchange Act of 1934.