CVE-2025-3108: Unsafe Deserialization in JsonPickleSerializer Enables Remote Code Execution in run-llama/llama_index

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-07-06 · updated 2026-06-17
Weakness: CWE-1112

Description

A critical deserialization vulnerability exists in the run-llama/llama_index library's JsonPickleSerializer component, affecting versions v0.12.27 through v0.12.40. This vulnerability allows remote code execution due to an insecure fallback to Python's pickle module. JsonPickleSerializer prioritizes deserialization using pickle.loads(), which can execute arbitrary code when processing untrusted data. Attackers can exploit this by crafting malicious payloads to achieve full system compromise. The root cause includes an insecure fallback mechanism, lack of validation or safeguards, misleading design, and violation of Python security guidelines.

Affected products

run-llama/llama_index: from 0.12.27 before 0.12.41 — fixed in 0.12.41

How to fix

Upgrade to a fixed version: run-llama/llama_index 0.12.41. Check the vendor advisory for mitigations.

References

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