High

Buffer overflow in pgvector parallel HNSW index build

IdentifiersCVE-2026-3172CWE-120

CVE-2026-3172 is a buffer overflow vulnerability in pgvector affecting versions 0.6.0 through 0.8.1. The flaw occurs during parallel HNSW index build operations. A database user can trigger the overflow in the course of building an HNSW index, leading to out-of-bounds memory access within the PostgreSQL server process. Based on the available description, successful exploitation can result in disclosure of sensitive data from other relations or a crash of the database server. Specific vulnerable functions or code paths are not provided in the available content.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows a database user to leak sensitive data from other relations, indicating a confidentiality impact across database objects beyond the attacker’s intended scope. The vulnerability can also crash the database server, causing denial of service. No evidence is provided in the available content for arbitrary code execution or privilege escalation beyond data disclosure and server instability.

Mitigation

If you can’t patch tonight, do this now.

If an immediate upgrade is not possible, reduce exposure by disabling or avoiding parallel HNSW index builds, restricting which database users are permitted to create or rebuild pgvector HNSW indexes, and limiting untrusted users’ ability to execute DDL involving pgvector indexes. Monitor for unexpected PostgreSQL crashes and suspicious index-build activity. Where feasible, isolate sensitive workloads and relations from users who can invoke pgvector indexing operations until a fixed version is deployed.

Remediation

Patch, then assume compromise.

Upgrade pgvector to a version newer than 0.8.1 that addresses CVE-2026-3172. Because the issue affects pgvector 0.6.0 through 0.8.1, remediation requires deploying a fixed release from the vendor or project maintainers once available in your distribution or build pipeline. If immediate upgrade guidance from the maintainer is available, follow that advisory.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

ACTIVITY FEED

Recent activity

29 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.

29 SOURCESView more in app

No news coverage yet. Advisories and community discussion only.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity29

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2026-3172

NVD

nvd.nist.gov/vuln/detail/CVE-2026-3172

MITRE CWE · CWE-120

cwe.mitre.org

github.com

github.com/pgvector/pgvector/issues/959