CVE-2026-10801: Weak Hash in ModelScope ms-swift PIL Image Cache

Technical summary

CVE-2026-10801 involves improper cryptographic hashing in the Template._save_pil_image function within swift/template/base.py. The component responsible for managing PIL image cache keys uses weak or inadequate hash functions (CWE-327, CWE-328), allowing an attacker to forge or manipulate cache entries. The vulnerability is constrained by local-only attack vector, high attack complexity, and requirement for local user privileges, making real-world exploitation difficult despite public disclosure of the issue.

Business impact

For teams using ms-swift in data preparation or model development pipelines, this vulnerability introduces subtle integrity risks—specifically the potential for undetected image substitution during preprocessing. While the CVSS score of 3.6 reflects low overall severity, the impact manifests as loss of data integrity rather than confidentiality or availability. This is particularly relevant in computer vision workflows where cache manipulation could silently alter training or evaluation datasets.

Affected systems

ModelScope ms-swift library versions up to and including 4.2.0 are affected. The vulnerability is specific to the PIL image caching mechanism and impacts any system using ms-swift for image handling. It does not affect other modelscope components or unrelated libraries. Organizations should inventory ms-swift usage across development, research, and production environments to determine exposure scope.

Exploitability

Exploitation requires local system access, existing user-level privileges, and high technical complexity. The attacker must understand the cache structure, hash generation logic, and image serialization format to successfully forge a malicious cache entry. Public disclosure exists, but the combination of high attack complexity and access requirements keeps real-world exploitation likelihood low. Most cloud and containerized deployments with proper isolation provide inherent protection.

Remediation

Update ms-swift to a version that resolves the weak hash implementation. A pull request addressing the issue is pending acceptance by the maintainers. Monitor the ModelScope GitHub repository for the next patched release and apply it to affected systems. Until a patch is available, restrict local system access to trusted users only and consider implementing file integrity monitoring on cache directories.

Patch guidance

Check the ModelScope ms-swift GitHub repository for an available security patch version beyond 4.2.0. When a fix is released, verify the release notes confirm that Template._save_pil_image hash functions have been updated to use cryptographically strong algorithms. Test the patched version in a development environment with your image processing workflows before production deployment. If no patch is yet available, consider pinning ms-swift to 4.2.0 and implementing compensating controls rather than upgrading to untested alternatives.

Detection guidance

Monitor file access patterns in ms-swift cache directories (typically .cache or .ms_cache locations) for unexpected modifications by non-owner processes. Implement file integrity monitoring on serialized PIL image cache files to detect unauthorized tampering. Log local system authentication and privilege escalation attempts. If using ms-swift in automated pipelines, validate image checksums before and after cache operations using a separate cryptographic hash function independent of the cache mechanism.

Why prioritize this

Assign this vulnerability low priority in most environments due to the local-only attack vector, user-level privilege requirement, and high technical complexity. However, increase priority if ms-swift processes untrusted or sensitive image data, if your threat model includes insider threats with local access, or if cache directories reside on shared multi-user systems. Development and research environments merit faster remediation than production due to ease of patching.

Risk score, explained

The CVSS 3.1 score of 3.6 (LOW) reflects the combination of local attack vector (AV:L), high attack complexity (AC:H), and low-privilege requirement (PR:L), which together substantially limit exploitability. The integrity impact (I:L) and availability impact (A:L) indicate only partial compromise of affected functions. The overall profile suggests the vulnerability is of concern primarily to defenders of systems with active insider threat or where cache integrity is critical to operations.

Frequently asked questions