CVE-2026-16240
PostgreSQL pg_basebackup can use backup manifest content as a format string
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.
INFO
Published Date :
Nov. 12, 2026, 3:17 p.m.
Last Modified :
Nov. 12, 2026, 3:17 p.m.
Remotely Exploit :
No
Source :
f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | LOW | f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 | ||||
| CVSS 3.1 | LOW | MITRE-CVE |
Solution
- Update PostgreSQL to version 18.7, 17.12, 16.16, 15.20, or 14.25.
- Apply vendor patches for PostgreSQL.
- Restrict access to pg_basebackup process.
- Review server compromise mitigation steps.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-16240.
| URL | Resource |
|---|---|
| https://www.postgresql.org/support/security/CVE-2026-16240/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-16240 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-16240
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-16240 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-16240 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
Nov. 12, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-134 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/16xxx/CVE-2026-16240.json">CVE-2026-16240</a> Added Reference https://www.postgresql.org/support/security/CVE-2026-16240/