CVE-2026-11479 Overview
CVE-2026-11479 affects yoanbernabeu grepai version 0.35.0, specifically the indexer/chunker.go file within the Qdrant Backend component. The vulnerability stems from the use of a weak hash algorithm [CWE-327]. An attacker operating remotely with low privileges can manipulate the affected functionality, though exploitation is rated as highly complex. The issue has been publicly disclosed, and a pull request to remediate the flaw is pending acceptance upstream. The vulnerability carries a low severity rating with limited impact on integrity and availability and no impact on confidentiality.
Critical Impact
Use of a weak hash algorithm in the Qdrant Backend chunker may allow an attacker to cause limited integrity or availability impact, though successful exploitation requires high attack complexity.
Affected Products
- yoanbernabeu grepai 0.35.0
- Affected component: Qdrant Backend (indexer/chunker.go)
- Fix status: Pull request #248 pending acceptance
Discovery Timeline
- 2026-06-08 - CVE-2026-11479 published to the National Vulnerability Database (NVD)
- 2026-06-08 - Last updated in NVD database
Technical Details for CVE-2026-11479
Vulnerability Analysis
The vulnerability resides in the chunker logic implemented in indexer/chunker.go, part of the grepai Qdrant Backend. The component relies on a cryptographically weak hash function to process or identify data chunks indexed into the Qdrant vector database. Weak hash algorithms produce predictable digests and are susceptible to collision attacks, which can undermine the integrity of indexed content. Within the chunker workflow, this weakness may allow an attacker to craft inputs that collide with legitimate chunk identifiers, potentially influencing indexing or retrieval outcomes.
The Common Weakness Enumeration classification is [CWE-327], Use of a Broken or Risky Cryptographic Algorithm. While the attack surface is reachable over the network, the exploit chain requires the attacker to control conditions that are difficult to manipulate reliably. Public disclosure has occurred through VulDB and the project's GitHub issue tracker, but no working exploit has been published.
Root Cause
The root cause is the selection of a weak hashing primitive within indexer/chunker.go. Cryptographic hash functions used for content identification in indexing pipelines should provide strong collision resistance. The implementation in grepai 0.35.0 does not meet this requirement, exposing the indexing flow to collision-based manipulation.
Attack Vector
An authenticated remote attacker with low privileges can interact with the grepai Qdrant Backend to submit content that exercises the vulnerable chunker. Crafting inputs that exploit the hash weakness requires significant effort, and no user interaction is needed. Successful exploitation results in limited integrity and availability impact on the indexed data, but does not expose confidential information.
No verified proof-of-concept code is publicly available. Refer to the GitHub Issue Tracker #247 and VulDB CVE-2026-11479 entries for additional technical context.
Detection Methods for CVE-2026-11479
Indicators of Compromise
- Anomalous chunk identifier collisions or duplicate hash values appearing within the Qdrant index that do not correlate with legitimate ingestion activity.
- Unexpected modifications to indexed documents or retrieval results returning content that does not match queried inputs.
- Repeated ingestion requests from a single low-privilege identity targeting the chunker endpoint of the Qdrant Backend.
Detection Strategies
- Audit the deployed version of grepai and confirm whether the indexer/chunker.go file matches the vulnerable 0.35.0 release.
- Monitor application logs for ingestion errors, hash collisions, or chunk overwrite events generated by the Qdrant Backend.
- Apply software composition analysis (SCA) to identify use of weak hash primitives such as MD5 or SHA-1 within the grepai dependency graph.
Monitoring Recommendations
- Capture and centralize grepai application logs, including chunker and Qdrant interaction events, for retrospective analysis.
- Track ingestion volume and chunk identifier distribution to surface statistical anomalies indicative of collision attempts.
- Alert on unauthorized changes to vector index contents, particularly modifications to existing chunk records.
How to Mitigate CVE-2026-11479
Immediate Actions Required
- Inventory all deployments of yoanbernabeu grepai and confirm whether version 0.35.0 is present in the environment.
- Restrict access to the grepai Qdrant Backend to trusted identities and reduce the privilege scope required for ingestion operations.
- Monitor the GitHub Pull Request #248 for merge status and prepare to update once the fix is released.
Patch Information
At the time of publication, the upstream fix is tracked in GitHub Pull Request #248 and awaits acceptance. No officially patched release of grepai is available yet. Administrators should subscribe to the GitHub Project Repository for release notifications and apply the corrected build once published.
Workarounds
- Limit network exposure of the grepai Qdrant Backend to internal trusted segments until a patched version is available.
- Apply strict authentication and rate limiting on ingestion endpoints to reduce the feasibility of collision-targeted submissions.
- Validate and sanitize ingested content out-of-band where feasible, and reconcile indexed chunks against authoritative source data.
- Consider replacing the weak hash function locally by building from a fork that integrates the pending pull request fix, where supported by internal change management.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
