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Fencer Intel
low 3.7

CVE-2026-16240 json

PostgreSQL pg_basebackup can use backup manifest content as a format string

published 2d ago modified 2d ago also EUVD-2026-124431

cvss
3.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

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.

Patch / fix

  • n/a PostgreSQL 14.25, 15.20, 16.16, 17.12, 18.7
  • postgresql-15 Debian 12 15.20-0+deb12u1
  • postgresql-17 Debian 13 17.12-0+deb13u1

debian advisories DEBIAN-CVE-2026-16240

  • postgresql14 openSUSE Tumbleweed 14.25-1.1
  • postgresql15 openSUSE Tumbleweed 15.20-1.1
  • postgresql16 openSUSE Tumbleweed 16.16-1.1
  • postgresql17 openSUSE Tumbleweed 17.12-1.1

opensuse advisories openSUSE-SU-2026:12550-1openSUSE-SU-2026:12551-1openSUSE-SU-2026:12552-1openSUSE-SU-2026:12553-1

  • postgresql15 Alpine 3.22, Alpine 3.21 15.20-r0
  • postgresql16 Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 16.16-r0
  • postgresql17 Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 17.12-r0
  • postgresql18 Alpine 3.24, Alpine 3.23 18.7-r0

alpine advisories ALPINE-CVE-2026-16240

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-16240 updated cvss 3.7

postgresql: postgresql: Information disclosure in pg_basebackup via crafted backup manifest

  • Red Hat Hardened Images postgresql18 18.6-1.hum1, postgresql17 17.11-1.2.hum1
    affected: workaround, no fix available
  • Red Hat Hardened Images libpq 18.7-0.1.hum1
    fixed: vendor fix RHSA-2026:99821

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2d ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-14).

CVSS scores

assigned by version score vector
CNA 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected products

  • n/a PostgreSQL

Classification

Weakness
  • CWE-134 Use of Externally-Controlled Format String

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.