CVE-2025-10156

Picklescan: ZIP archive scan bypass is possible through non-exhaustive Cyclic Redundancy Check

Severity: High
Affected Users: Any organization or individual using Picklescan to analyze PyTorch models or other files distributed as ZIP archives for malicious pickle content.
Impact Details: Attackers can craft malicious PyTorch models containing embedded pickle payloads, package them into ZIP archives, and intentionally introduce CRC errors. This would cause Picklescan to fail to analyze the archive, while PyTorch is still able to load the model (depending on its configuration regarding CRC checks). This creates a significant vulnerability where malicious code can be distributed and potentially executed without detection by Picklescan.
Ex: Picklescan on HuggingFace goes into error (https://huggingface.co/jinaai/jina-embeddings-v2-base-en/tree/main)

Recommendations:
Picklescan should not fail on Bad CRC check, especially if Pytorch is not checking CRC.
Relaxed Zipfile is perfect to fix this issue:

--- picklescan/src/picklescan/relaxed_zipfile.py
+++ picklescan/src/picklescan/relaxed_zipfile.py
@@ class RelaxedZipFile(zipfile.ZipFile):
         try:
             # Skip the file header:
             fheader = zef_file.read(sizeFileHeader)
             if len(fheader) != sizeFileHeader:
                 raise zipfile.BadZipFile("Truncated file header")

             fheader = struct.unpack(structFileHeader, fheader)
             if fheader[_FH_SIGNATURE] != stringFileHeader:
                 raise zipfile.BadZipFile("Bad magic number for file header")

             zef_file.read(fheader[_FH_FILENAME_LENGTH])
             if fheader[_FH_EXTRA_FIELD_LENGTH]:
                 zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])

-            return zipfile.ZipExtFile(zef_file, mode, zinfo, pwd, True)
+
+            # Create the ZipExtFile and disable CRC check
+            ext_file = zipfile.ZipExtFile(zef_file, mode, zinfo, pwd)
+            # Monkey-patch to skip CRC validation
+            ext_file._expected_crc = None
+            return ext_file

         except BaseException:
             zef_file.close()
             raise

CVE-2025-10156 has a CVSS score of 7.5 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.31); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-10156? CVE-2025-10156 is a critical-severity security vulnerability in picklescan (pip), affecting versions <= 0.0.30. It is fixed in 0.0.31.
2. How severe is CVE-2025-10156? CVE-2025-10156 has a CVSS score of 7.5 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of picklescan are affected by CVE-2025-10156? picklescan (pip) versions <= 0.0.30 is affected.
4. Is there a fix for CVE-2025-10156? Yes. CVE-2025-10156 is fixed in 0.0.31. Upgrade to this version or later.
5. Is CVE-2025-10156 exploitable, and should I be worried? Whether CVE-2025-10156 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-10156 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-10156? Upgrade picklescan to 0.0.31 or later.