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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"TcfEuV2CoreSegment decoder incorrectly accepts corrupt PublisherRestrictions","articleBody":"Attached is a real-world example of a TCF string where the `PublisherRestrictions` field has been corrupted due to a bug in the CMP.\nThe issue is the your reference decoder accepts this string.\n\n- There is logic in the `PublisherRestrictions` decoder `AbstractEncodableBitStringDataType::getHardFailIfMissing()` that allows this field to be missing, however the field is not missing - it is corrupt.\n\n- This means that anyone who uses this decoder, or has their own direct port of it, may be unknowingly ignoring the `PublisherRestrictions` field.\n\n- Also, this logic only works because `PublisherRestrictions` is the last data field.\n\nOur custom decoder rejects this string and this has led to confusion as the string is accepted by the popular online test decoders (except for https://iabtcf.com/#/decode, which also rejects this string) .\n\nPossible Solution:\n- The decoder needs to distinguish between 'missing' and 'corrupt'.\n\n\nExample string:\n```\nCQLvHAAQLvHAAAKA4DENBaFsAP_gAEPgAAwIKxtX_G9_bXlr8X736ftkeY1f99h77sQxBhZBk-4FzLvW_JwX32E7NA36tqYKmRIAu3TBIQNlHJDURVCgaogVrTDMaEyUoTtKJ6BkiFMRY2dYCFxvm4tjeQCY5vr991d52R-tbdrs3dzyy4hnv3a9_-S1WJCdA5-tDfv9bROb89IO5_x8v4v4_N7pE2_eT1l_tWvp7D9-ctv_9XX99_fbff9Pn_-uB_-_X__f_H37grAAQYCABAEAQICAAAAAQAAEAAEABAAAAAAACgAABEEAAEDAAAQAIAQAAABAABAAAAIAAAAAgACAAAAAEAgAAAACgADAAAAAAAYAAAMAEgIAAAAAQACmABAIFAAEJAFAEACEAEEAIQAABAEACAEABRwBAACBAoAAAQAAEAAAFgIDgAQEpAgACIgEAAAIAEAggAAEQjYACCAASCqqBAiiCAQLBoQFPaQAkgBACDgmQAgABQAHAAsA\n```\n\nThe line of code in question is:\nhttps://github.com/IABTechLab/iabgpp-java/blob/d3d5017cd721e0a9d52ab7080d0f48e6be96db82/iabgpp-encoder/src/main/java/com/iab/gpp/encoder/segment/TcfEuV2CoreSegment.java#L70\n\nPassing `false` to the `EncodableArrayOfFixedIntegerRanges` constructor allows it to accept corrupt data.","author":{"url":"https://github.com/jamescooper-blis","@type":"Person","name":"jamescooper-blis"},"datePublished":"2025-03-07T19:22:46Z","url":"https://github.com/IABTechLab/iabgpp-java/issues/67"}