pgvector: Out-of-bounds write in IVFFlat index build
Summary
pgvector, an open-source PostgreSQL extension for vector similarity search, contains an out-of-bounds write in the IVFFlat index build. A database user who is allowed to create an IVFFlat index can write data past the end of a buffer, which can lead to arbitrary code execution. The CVE record notes that PostgreSQL installations are not affected by default.
Affected
- pgvector before 0.8.7 (CVE record: 0 to < 0.8.7; upstream issue: 0.8.6 and below)
Fixed in
- pgvector 0.8.7
- Red Hat: RHSA-2026:88359 (PostgreSQL 16 packages) and RHSA-2026:88360 (PostgreSQL 18 packages) ship pgvector 0.8.7
Workaround
Unknown. No vendor-documented workaround. Restricting who can create or reindex IVFFlat indexes reduces risk (not vendor-confirmed).
Exploitation
- No evidence of exploitation found in the sources reviewed.
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- No public proof of concept found.
Our recommendation
- Upgrade pgvector to 0.8.7 or later, including container images and OS packages.
- Confirm the installed version on all PostgreSQL servers.
- Review which database roles can create or reindex IVFFlat indexes and limit these rights.
- Separate migration roles from application roles where possible.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- pgvector issue #1036: Buffer overflow with IVFFlat index build github.com
- pgvector fix commit ee00d39 github.com
- PostgreSQL.org: pgvector 0.8.7 released www.postgresql.org
- Red Hat RHSA-2026:88359 access.redhat.com
- Vulners: RHSA-2026:88360 (CVE-2026-103484) vulners.com
- Vulners: SUSE CVE-2026-103484 vulners.com
- The Build: The vector that lied about its dimensions thebuild.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 22:55.
Original description (NVD)
IVFFlat index build in pgvector before 0.8.7 allows a database user to write data out-of-bounds, which can lead to arbitrary code execution.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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