A denial of service vulnerability exists in the pyasn1 BER/CER/DER decoder used by dstack, caused by unbounded long-form tag IDs. The decoder accumulates continuation octets without an upper limit, allowing crafted inputs to cause excessive CPU consumption. On Python 3.11 and later, oversized tag IDs can also trigger unhandled ValueErrors, potentially bypassing error handling. This affects decoding of untrusted BER/CER/DER inputs. The issue is fixed in version 0.20.27 by limiting tag ID length and improving error handling.