Muhammara has a NULL pointer dereference in LZWDecode filter when DecodeParms omits EarlyChange key

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

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 <= 6.0.4 (latest) Vulnerability Details File: src/deps/PDFWriter/PDFParser.cpp line 2107 When inDecodeParams is non-NULL but lacks the EarlyChange key: 1. QueryDictionaryObject() returns NULL 2. PDFObjectCastPtr<PDFInteger(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 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 pocmuhammaralzwnull.js

Published by the source

26 Jun 2026, 20:55 UTC

Last modified by the source

26 Jun 2026, 21:00 UTC

Source last checked

26 Oct 2026, 12:56 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-fhp4-pr5j-46m5

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-fhp4-pr5j-46m5

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# Patch Next advisory brief: GHSA-fhp4-pr5j-46m5

Advisory: Muhammara has a NULL pointer dereference in LZWDecode filter when DecodeParms omits EarlyChange key
IDs: GHSA-fhp4-pr5j-46m5
Record: https://patchnext.com/advisories/ghsa-fhp4-pr5j-46m5 (revision 2, source checked 26 Oct 2026, 12:56 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: muhammara 6.0.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm muhammara: affected <= 6.0.4; fixed in 6.0.5

## Suggested inspection (read-only)
- `npm ls muhammara --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on muhammara.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-fhp4-pr5j-46m5 (OSV record GHSA-fhp4-pr5j-46m5 lists affected ranges: npm muhammara >=0 <6.0.5 (fixed))
- Verified: https://github.com/advisories/GHSA-fhp4-pr5j-46m5 (GitHub-reviewed advisory GHSA-fhp4-pr5j-46m5 lists affected ranges: npm muhammara >=0 <=6.0.4)

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