CVE
PostgreSQL memory disclosure in pg_basebackup via backup manifest
- Exploited
- No known exploitation
- Fix
- Fixed in 18.7, 17.12, 16.16, 15.20, 14.25
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 18.7, 17.12, 16.16, 15.20, 14.25.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.27% · 19th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 38/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
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.
cve.now Index
- Exploitation0/40No signal
- Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Unknown: No advisory context yet
- Reach17/20Affects PostgreSQL (a widely deployed server, runtime, framework or database)
- Severity3.7/10CVSS 3.7
- No patch0/5No signal
What would change the score
- Would score about 83 if added to CISA KEV
- Would score about 78 if CISA's SSVC rates exploitation active
- Would score about 43 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 18.7, 17.12, 16.16, 15.20, 14.25.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-16240 (PostgreSQL pg_basebackup can use backup manifest content as a format string), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-16240 (entry last updated 2026-11-12):
Affected:
- n/a PostgreSQL: from 18, fixed in 18.7; from 17, fixed in 17.12; from 16, fixed in 16.16; from 15, fixed in 15.20; fixed in 14.25
Fixed versions: 18.7, 17.12, 16.16, 15.20, 14.25.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-16240 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-16240 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://www.postgresql.org/support/security/CVE-2026-16240/
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-16240
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-16240"}.Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- n/a PostgreSQL
From 18 · fixed in 18.7; From 17 · fixed in 17.12; From 16 · fixed in 16.16; From 15 · fixed in 15.20; fixed in 14.25
Evidence 3
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Link
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-16240
Is CVE-2026-16240 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-16240?
PostgreSQL: from 18 before 18.7; from 17 before 17.12; from 16 before 16.16; from 15 before 15.20; before 14.25.Source: cve.now feed data
How do I fix CVE-2026-16240?
Upgrade to a fixed version: 18.7, 17.12, 16.16, 15.20, 14.25.Source: cve.now feed data