# CVE-2022-39381: Muhammara null pointer dereference in PDF append

Source: https://junglewise.ai/threats/cve-2022-39381-muhammara-null-pointer-dereference-in-pdf-append  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-11-02. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2022-39381 · Severity: low · CVSS 3.1 · Published 2022-11-02

Muhammara and Hummus are JavaScript libraries used to programmatically manipulate PDF documents. A maliciously crafted PDF file can trigger a crash when an application attempts to append it to another PDF, causing a denial of service. Affected applications using these libraries may become unavailable if processing untrusted PDF inputs.

Technologies: [hummus (npm)](https://junglewise.ai/threats/technologies/hummus), [muhammara (npm)](https://junglewise.ai/threats/technologies/muhammara). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2022-39381 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2022-39381 being exploited in the wild.

**How severe is CVE-2022-39381?** Low severity, with a CVSS score of 3.1, published 2 November 2022.

**Which products and versions are affected?** hummus (npm) SEMVER:introduced=0,fixed=1.0.111; muhammara (npm) SEMVER:introduced=0,fixed=2.6.0.

**Is there a fix for CVE-2022-39381?** Yes. hummus (npm): upgrade to 1.0.111 or later; muhammara (npm): upgrade to 2.6.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2022-39381 attacked?** It is attacked over the network.

**Am I affected by CVE-2022-39381?** Check whether you run hummus (npm) or muhammara (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- hummus (npm): upgrade to 1.0.111 or later

  ```sh
  npm install hummus@1.0.111
  ```

- muhammara (npm): upgrade to 2.6.0 or later

  ```sh
  npm install muhammara@2.6.0
  ```


## Technical details

The vulnerability is an unchecked return value leading to null pointer dereference in PDFDocumentHandler.cpp. The root cause occurs when the library fails to validate that a function call returns a valid pointer before dereferencing it during PDF append operations. An attacker can exploit this by supplying a maliciously crafted PDF file that causes the vulnerable function to return NULL. The attack requires no authentication or user interaction and is reachable over the network. Successful exploitation results in a denial of service (application crash). Muhammara patched this issue in version 2.6.0; Hummus has not released a patch.

## Affected products

- Julian Hille Muhammara before 2.6.0
- Gal Kahana Hummus all versions

## Identifiers

- CVE-2022-39381
- GHSA-rcrx-fpjp-mfrw

## Timeline

- 2022-11-02: disclosed: Advisory published on GitHub and OSV
- 2022-11-02: patched: Muhammara patched in version 2.6.0

## References

- [https://github.com/julianhille/MuhammaraJS/security/advisories/GHSA-rcrx-fpjp-mfrw](https://github.com/julianhille/MuhammaraJS/security/advisories/GHSA-rcrx-fpjp-mfrw)

## Related threats

- [Muhammara NULL pointer dereference in LZWDecode filter](https://junglewise.ai/threats/muhammara-null-pointer-dereference-in-lzwdecode-filter-ec14f183)
- [muhammara and hummus null pointer dereference in PDFStreamForResponse](https://junglewise.ai/threats/cve-2022-25885-muhammara-and-hummus-null-pointer-dereference-in)
- [muhammara and Hummus NULL pointer dereference denial of service](https://junglewise.ai/threats/cve-2022-25892-muhammara-and-hummus-null-pointer-dereference-denial-of-service)