CVE-2026-16240

PostgreSQL pg_basebackup can use backup manifest content as a format string

  • Low 3.7

Description

Use of externally-controlled format string in PostgreSQL pg_basebackup allows an attacker having already compromised a server to achieve disclosure from pg_basebackup memory, via backup manifest bytes. The vulnerability does not return the improperly-read bytes back to the attacker's server, so a successful attack would need separate implementation-specific secrets for that. Integrity impact is unlikely; in particular, the applicable formatter does not support %n. Versions before PostgreSQL 18.7, 17.12, 16.16, 15.20, and 14.25 are affected.

Key facts

Published
12 Nov 2026
Last changed
12 Nov 2026
Assigned by
PostgreSQL
EPSS
0.269% likely to be exploited in the next 30 days, higher than 19.279% of CVEs (scores for 15 Nov 2026)
SSVC (CISA)
Exploitation: none; Automatable: no; Technical impact: partial

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 3.7CVSS 3.1, Lowfrom the CNA (PostgreSQL)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
n/aPostgreSQL
  • Default status: unaffected
  • 18 up to but excluding 18.7 (affected)
  • 17 up to but excluding 17.12 (affected)
  • 16 up to but excluding 16.16 (affected)
  • 15 up to but excluding 15.20 (affected)
  • 0 up to but excluding 14.25 (affected)

Timeline

  1. 12 Nov 2026 Published

Weakness

References