CVE-2026-119197 is a denial of service vulnerability in pyasn1 versions 0.6.4 and earlier, affecting the decoding of binary ASN.1 REAL values with large mantissas. The decoding process has quadratic time complexity due to inefficient byte processing, causing excessive CPU consumption. This impacts BER, CER, and DER decoders using the vulnerable RealPayloadDecoder. The vulnerability can be triggered when an application decodes attacker-controlled ASN.1 data containing REAL values. The issue was fixed in pyasn1 version 0.6.5 by optimizing the decoding loop.