GHSA-fhp4-pr5j-46m5 Muhammara has a NULL pointer dereference in LZWDecode filter when DecodeParms omits EarlyChange key

• npm muhammara: < 6.0.5 → fixed in 6.0.5

Summary A NULL pointer dereference vulnerability exists in `PDFParser::CreateFilterForStream()` when processing a PDF stream with `/Filter /LZWDecode` and a `/DecodeParms` dictionary that does not contain the `EarlyChange` key. This causes an access violation (0xC0000005) and crashes the process. Affected Version muhammara earlyObj( QueryDictionaryObject(inDecodeParams, "EarlyChange") ); early = earlyObj->GetValue(); // NULL dereference when EarlyChange key is absent } ``` When `inDecodeParams` is non-NULL but lacks the `EarlyChange` key: 1. `QueryDictionaryObject()` returns NULL 2. `PDFObjectCastPtr(NULL)` wraps NULL 3. `earlyObj->GetValue()` dereferences NULL → crash PoC 460-byte malicious PDF triggers crash via `startReadingFromStream()`: • PDF contains `/Filter /LZWDecode` with `/DecodeParms >` (empty, no EarlyChange) • Exit code: `0xC0000005` (Access Violation) Fix ```cpp if (earlyObj) early = earlyObj->GetValue(); ``` Impact Any application accepting untrusted PDFs and using muhammara to read stream contents is vulnerable to DoS. Similar to: CVE-2022-41957, CVE-2022-39381 PoC File poc_muhammara_lzw_null.js