CVE-2025-6211: MD5 Hash Collision in run-llama/llama_index

Severity: medium (CVSS 6.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-07-10 · updated 2026-06-17
Weakness: CWE-440

Description

A vulnerability in the DocugamiReader class of the run-llama/llama_index repository, up to version 0.12.28, involves the use of MD5 hashing to generate IDs for document chunks. This approach leads to hash collisions when structurally distinct chunks contain identical text, resulting in one chunk overwriting another. This can cause loss of semantically or legally important document content, breakage of parent-child chunk hierarchies, and inaccurate or hallucinated responses in AI outputs. The issue is resolved in version 0.3.1.

Affected products

run-llama/llama_index: before 0.3.1 — fixed in 0.3.1

How to fix

Upgrade to a fixed version: run-llama/llama_index 0.3.1. Check the vendor advisory for mitigations.

References

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