CVE-2026-16240

PostgreSQL pg_basebackup can use backup manifest content as a format string

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.

Version Information

Affected Version Fixed In Fix Published
18 18.7 2026-11-12
17 17.12 2026-11-12
16 16.16 2026-11-12
15 15.20 2026-11-12
14 14.25 2026-11-12

For more information about PostgreSQL versioning, please visit the versioning page.

CVSS 3.0

Overall Score 3.7
Component client
Vector AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

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