PostgreSQL pg_basebackup and pg_rewind can overwrite unrelated files of origin superuser choice
Summary
| CVE | CVE-2026-6475 |
|---|---|
| State | PUBLISHED |
| Assigner | PostgreSQL |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-14 14:16:25 UTC |
| Updated | 2026-05-18 15:02:12 UTC |
| Description | Symlink following in PostgreSQL pg_basebackup plain format and in pg_rewind allows an origin superuser to overwrite local files, e.g. /var/lib/postgres/.bashrc, that hijack the operating system account. It will remain the case that starting the server after these commands implicitly trusts the origin superuser, due to features like shared_preload_libraries. Hence, the attack has practical implications only if one takes relevant action between these commands and server start, like moving the files to a different VM or snapshotting the VM. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected. |
Risk And Classification
Primary CVSS: v3.1 8.8 HIGH from f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.000490000 probability, percentile 0.152790000 (date 2026-05-25)
Problem Types: CWE-61 | CWE-61 UNIX Symbolic Link (Symlink) Following
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 | Secondary | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Postgresql | Postgresql | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Na | PostgreSQL | affected 18 18.4 rpm | Not specified |
| CNA | Na | PostgreSQL | affected 17 17.10 rpm | Not specified |
| CNA | Na | PostgreSQL | affected 16 16.14 rpm | Not specified |
| CNA | Na | PostgreSQL | affected 15 15.18 rpm | Not specified |
| CNA | Na | PostgreSQL | affected 14.23 rpm | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.postgresql.org/support/security/CVE-2026-6475 | f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 | www.postgresql.org | Patch, Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: The PostgreSQL project thanks Valery Gubanov, XlabAI Team of Tencent Xuanwu Lab, Atuin Automated Vulnerability Discovery Engine, Zhanpeng Liu (pkugenuine(at)gmail(dot)com), Guannan Wang (wgnbuaa(at)gmail(dot)com), and Guancheng Li (lgcpku(at)gmail(dot)com) for reporting this problem. (en)
There are currently no legacy QID mappings associated with this CVE.