CVE-2026-6638

Description

SQL injection in PostgreSQL logical replication ALTER SUBSCRIPTION ... REFRESH PUBLICATION allows a subscriber table creator to execute arbitrary SQL with the subscription's publication-side credentials. The attack takes effect at the next REFRESH PUBLICATION. Within major versions 16, 17, and 18, minor versions before PostgreSQL 18.4, 17.10, and 16.14 are affected. Versions before PostgreSQL 16 are unaffected.

CVSS v3.1 Score

3.7

LOW

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0002

Probability of exploitation

0.07%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-89 SQL Injection

Affected Products

Vendor	Product	Versions
postgresql	postgresql	16.0 — 16.14
postgresql	postgresql	17.0 — 17.10
postgresql	postgresql	18.0 — 18.4

References

Advisories & Patches

https://www.postgresql.org/support/security/CVE-2026-6638/

Frequently Asked Questions

What is CVE-2026-6638? +

SQL injection in PostgreSQL logical replication ALTER SUBSCRIPTION ... REFRESH PUBLICATION allows a subscriber table creator to execute arbitrary SQL with the subscription's publication-side credentials. The attack takes effect at the next REFRESH PUBLICATION. Within major versions 16, 17, and 18, minor versions before PostgreSQL 18.4, 17.10, and 16.14 are affected. Versions before PostgreSQL 16 are unaffected. It has a CVSS v3.1 base score of 3.7 (LOW).

How severe is CVE-2026-6638? +

CVE-2026-6638 has a CVSS v3.1 score of 3.7 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-6638? +

CVE-2026-6638 affects products from postgresql, specifically: postgresql. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-6638? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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