# CVE-2026-120454: The Sleuth Kit NULL pointer dereference in LZVN decompression

Source: https://junglewise.ai/threats/cve-2026-120454-the-sleuth-kit-through-4-15-0-contains-a-null-pointer  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-02. Updated: 2026-11-02  
License: CC BY 4.0 with a link back

CVE-2026-120454 · Severity: medium · CVSS 5.5 · Published 2026-11-02

The Sleuth Kit is a digital forensics tool used to analyze file systems and recover data from disk images. A flaw in its HFS+ compression handling allows an attacker to crash the tool by supplying a maliciously crafted disk image, causing denial of service during forensic investigations. The vulnerability occurs when the tool processes specially crafted compression metadata that triggers a memory allocation failure.

Technologies: [Sleuthkit The Sleuth Kit](https://junglewise.ai/threats/technologies/the-sleuth-kit). Vendors: [Sleuthkit](https://junglewise.ai/threats/vendors/sleuthkit).

## Quick answers

**Is CVE-2026-120454 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120454 being exploited in the wild.

**How severe is CVE-2026-120454?** Medium severity, with a CVSS score of 5.5, published 2 November 2026.

**Which products and versions are affected?** Sleuthkit The Sleuth Kit through 4.15.0.

**Is there a fix for CVE-2026-120454?** No fixed version is recorded yet. Avoid processing untrusted HFS+ disk images with The Sleuth Kit until a patched version is available; if forensic analysis of such images is necessary, run the tool in an isolated environment to contain potential crashes. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-120454 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-120454?** Check whether you run Sleuthkit The Sleuth Kit 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


Avoid processing untrusted HFS+ disk images with The Sleuth Kit until a patched version is available; if forensic analysis of such images is necessary, run the tool in an isolated environment to contain potential crashes.

## Technical details

The vulnerability is a NULL pointer dereference (CWE-476) combined with an uncontrolled allocation size (CWE-789) in the decmpfs_decompress_lzvn_attr() function. When processing an HFS+ file with a com.apple.decmpfs attribute of type LZVN compression (type 7), if the uncompressed_size field is set to an extremely large value (e.g., 0x7fffffffffffffff), the allocation fails and returns NULL; the code then passes this NULL pointer directly to lzvn_decode_buffer() without checking, causing a crash. The attack requires only a crafted HFS+ image; no authentication or user interaction is needed beyond opening the image.

## Affected products

- Sleuthkit The Sleuth Kit through 4.15.0

## Timeline

- 2026-11-02: disclosed
- 2026-11-02: advisory

## References

- [https://github.com/sleuthkit/sleuthkit/blob/sleuthkit-4.15.0/tsk/fs/decmpfs.c](https://github.com/sleuthkit/sleuthkit/blob/sleuthkit-4.15.0/tsk/fs/decmpfs.c)
- [https://github.com/sleuthkit/sleuthkit/issues/3583](https://github.com/sleuthkit/sleuthkit/issues/3583)

## Related threats

- [Sleuth Kit out-of-bounds read in ISO9660 SUSP parser](https://junglewise.ai/threats/cve-2026-40026-sleuth-kit-out-of-bounds-read-in-iso9660-susp-parser)
- [Sleuth Kit out-of-bounds read in APFS keybag parser](https://junglewise.ai/threats/cve-2026-40025-sleuth-kit-out-of-bounds-read-in-apfs-keybag-parser)
- [The Sleuth Kit path traversal in tsk_recover](https://junglewise.ai/threats/cve-2026-40024-the-sleuth-kit-path-traversal-in-tsk-recover)