# CVE-2026-116489: Timescale pgvectorscale before 0.9.1 Type Confusion via Unqualified DiskANN Operator Classes

Status: published. Published: 2026-10-26. Updated: 2026-11-04.

Timescale pgvectorscale before 0.9.1 contains a type confusion vulnerability that allows low-privileged database users to corrupt memory by shadowing pgvector's vector type or operators. Attackers with CREATE privilege on the vectorscale schema can pre-create shadow objects, then build and query DiskANN indexes over crafted values to cause out-of-bounds reads and writes, disclosing memory, crashing the server, or escalating privileges.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/timescale/pgvectorscale/pull/280
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/timescale/pgvectorscale/commit/1c7cb1cab919ac122f901f163a71f69a264a8f81
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/timescale/pgvectorscale/commit/59d2f573dbd7a1446728ac547576d22f5b05cfaa
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/timescale/pgvectorscale/commit/f42f8cf29c92111add863ccf3255b3bf23fb51cd

## Affected products and versions

- timescale / pgvectorscale: ≥ 0; < 0.9.1 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7.7 (high); CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H; source: CNA: VulnCheck

- CVSS 4.0: 7.7 (high); CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.50% as of 2026-11-04; percentile 42.82%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-843

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/timescale/pgvectorscale/pull/280 (CNA: VulnCheck; issue-tracking, patch)

- https://github.com/timescale/pgvectorscale/commit/1c7cb1cab919ac122f901f163a71f69a264a8f81 (CNA: VulnCheck; patch)

- https://github.com/timescale/pgvectorscale/commit/59d2f573dbd7a1446728ac547576d22f5b05cfaa (CNA: VulnCheck; patch)

- https://github.com/timescale/pgvectorscale/commit/f42f8cf29c92111add863ccf3255b3bf23fb51cd (CNA: VulnCheck; patch)

- https://github.com/timescale/pgvectorscale/blob/0.9.0/pgvectorscale/src/access_method/mod.rs#L208-L231 (CNA: VulnCheck; technical-description)

- https://github.com/timescale/pgvectorscale/blob/0.9.0/pgvectorscale/src/access_method/pg_vector.rs#L133-L151 (CNA: VulnCheck; technical-description)

- https://github.com/timescale/pgvectorscale/blob/0.9.0/pgvectorscale/src/access_method/build.rs#L253 (CNA: VulnCheck; technical-description)

- https://github.com/timescale/pgvectorscale/releases/tag/0.9.1 (CNA: VulnCheck; release-notes)

- https://github.com/timescale/pgvectorscale (CNA: VulnCheck; product)

- https://www.vulncheck.com/advisories/timescale-pgvectorscale-before-0.9.1-type-confusion-via-unqualified-diskann-operator-classes (CNA: VulnCheck; third-party-advisory)

- https://github.com/timescale/pgvectorscale (disclosure@vulncheck.com)

- https://github.com/timescale/pgvectorscale/blob/0.9.0/pgvectorscale/src/access_method/build.rs#L253 (disclosure@vulncheck.com)

- https://github.com/timescale/pgvectorscale/blob/0.9.0/pgvectorscale/src/access_method/mod.rs#L208-L231 (disclosure@vulncheck.com)

- https://github.com/timescale/pgvectorscale/blob/0.9.0/pgvectorscale/src/access_method/pg_vector.rs#L133-L151 (disclosure@vulncheck.com)

- https://github.com/timescale/pgvectorscale/commit/1c7cb1cab919ac122f901f163a71f69a264a8f81 (disclosure@vulncheck.com)

- https://github.com/timescale/pgvectorscale/commit/59d2f573dbd7a1446728ac547576d22f5b05cfaa (disclosure@vulncheck.com)

- https://github.com/timescale/pgvectorscale/commit/f42f8cf29c92111add863ccf3255b3bf23fb51cd (disclosure@vulncheck.com)

- https://github.com/timescale/pgvectorscale/pull/280 (disclosure@vulncheck.com)

- https://github.com/timescale/pgvectorscale/releases/tag/0.9.1 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/timescale-pgvectorscale-before-0.9.1-type-confusion-via-unqualified-diskann-operator-classes (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-116489; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116489; retrieved 2026-11-04; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-116489; retrieved 2026-11-04; source updated Not reported

Revision: 29d48519ca174f20633f95ccb516145a7f9f52a29badcd766e1093aa0e8f20e5

Canonical: https://y2.dev/cve/CVE-2026-116489

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