CVE-2023-45853 is a high-severity (CVSS 8.8) CWE-190 vulnerability in pyminizip. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
pyminizip affected by zlib's integer overflow/heap based buffer overflow vulnerability due to vulnerable dependency
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-45853.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
pyminizipReal-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
MiniZip in zlib through 1.3 has an integer overflow and resultant heap-based buffer overflow in zipOpenNewFileInZip4_64 via a long filename, comment, or extra field. NOTE: MiniZip is not a supported part of the zlib product. NOTE: pyminizip through 0.2.6 is also vulnerable because it bundles an affected zlib version, and exposes the applicable MiniZip code through its compress API.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pyminizip | all versions | No fix |
Affected Products
pyminizipsmihicazlibzlibDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyminizip, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of pyminizip for CVE-2023-45853. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat Enterprise Linux default configuration doesn't expose zlib through any network services. Additionally, the user would need to be tricked into opening the crafted file from an attacker to be successful. The impact for Confidentiality, Integrity, and Availability is limited to the scope of the process and user…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat JBoss Core Services | zlib | RHSA-2023:7626 |
Frequently Asked Questions
Is CVE-2023-45853 in your dependencies?
Find it across PyPI, including transitive dependencies.