CVE-2026-119197 is a denial of service vulnerability in pyasn1 versions 0.6.4 and earlier. It arises from a quadratic-complexity loop in decoding binary ASN.1 REAL values with large mantissas, causing excessive CPU consumption. The flaw affects BER, CER, and DER decoders using the RealPayloadDecoder. An attacker supplying crafted ASN.1 data with large REAL values can cause CPU exhaustion during decoding. The issue is fixed in pyasn1 0.6.5. Applications using affected pyasn1 versions should upgrade or limit input containing REAL values.