MLX has heap-buffer-overflow in load()

Exploitation

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

CVSS 4.0

5.5 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P · score source

EPSS

• CVE-2025-62608: 0.56% estimated exploitation activity in the next 30 days; percentile 46.68 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Heap buffer overflow in mlx::core::load() when parsing malicious NumPy .npy files. Attacker-controlled file causes 13-byte out-of-bounds read, leading to crash or information disclosure. Environment: - OS: Ubuntu 20.04.6 LTS - Compiler: Clang 19.1.7 Vulnerability The parser reads a 118-byte header from the file, but line 268 uses std::string(&buffer[0]) which stops at the first null byte, creating a 20-byte string instead. Then line 276 tries to read header[34] without checking the length first, reading 13 bytes past the allocation. Location: mlx/io/load.cpp:268,276 Bug #1 (line 268): Bug #2 (line 276): Possible Fix PoC AddressSanitizer Output (with instrumented build): Impact - Attack vector: Malicious .npy file (model weights, datasets, checkpoints) - Affects: MLX users on all platforms who call the vulnerable methods with unsanitized input. - Result: Application crash + potential 13-byte heap leak --- Credits: - Markiyan Melnyk (ARIMLABS) - Mykyta Mudryi (ARIMLABS) -…

Published by the source

21 Nov 2025, 18:02 UTC

Last modified by the source

6 Jun 2026, 00:45 UTC

Source last checked

26 Oct 2026, 13:44 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-w6vg-jg77-2qg6

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-w6vg-jg77-2qg6

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# Patch Next advisory brief: CVE-2025-62608

Advisory: MLX has heap-buffer-overflow in load()
IDs: CVE-2025-62608, GHSA-w6vg-jg77-2qg6
Record: https://patchnext.com/advisories/cve-2025-62608 (revision 3, source checked 26 Oct 2026, 13:44 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: mlx 0.29.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI mlx: affected <= 0.29.3; fixed in 0.29.4

## Suggested inspection (read-only)
- `python -m pip show mlx`: prints the installed version. Run with the environment that serves production active.

## 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 mlx.
- 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-w6vg-jg77-2qg6 (OSV record GHSA-w6vg-jg77-2qg6 lists affected ranges: PyPI mlx >=0 <0.29.4 (fixed))
- Verified: https://github.com/advisories/GHSA-w6vg-jg77-2qg6 (GitHub-reviewed advisory GHSA-w6vg-jg77-2qg6 lists affected ranges: PyPI mlx >=0 <=0.29.3)

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