Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Search

GHSA-52vm-mxx8-f227

HighCVSS 7.7 / 10
Published Jul 9, 2026·Last modified Jul 9, 2026
Affected Components(0)

No affected components available

Description

Impact

In Phantom <= 1.3.0, when PHANTOM_OUTPUT_DIR was unset (the default), the MCP tools accepted arbitrary absolute output paths with no confinement. Anything able to send tool calls (e.g. an AI agent driving the MCP interface) could write or overwrite arbitrary files the process user can write — including shell startup files (~/.zshrc) or a Reaper __startup.lua, which is effectively local code execution on a developer workstation.

Separately, the stem-separation and render paths decoded input audio with no size/duration cap (the analysis path was already guarded). A small, highly compressed FLAC/OGG could expand to multi-gigabyte PCM, causing memory-exhaustion DoS, and widened exposure to decoder bugs including libsndfile CVE-2026-37555.

Patches

Fixed in 1.3.1:

  • File writes are always confined to PHANTOM_OUTPUT_DIR (default ~/.phantom/output); symlinks resolved and re-verified on the final path.
  • Decode/duration/size guards mirrored onto the separation and render paths (plus ffmpeg -max_alloc/-t/-fs).
  • Atomic O_CREAT|O_EXCL output creation in reference matching and symlink-TOCTOU hardening on confined input reads.

Workarounds

Set PHANTOM_OUTPUT_DIR (and optionally PHANTOM_AUDIO_DIR) to dedicated directories before starting the server.

Credit

Found during an internal security audit.

Risk Scores
Base Score
7.7

The vulnerability requires local access to the device to be exploited. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data.

Threat Intelligence
7.1

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
N/A

Probability that this vulnerability will be exploited in the wild within the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard