CVE-2026-107350
Authentication bypass via second StartupMessage during SCRAM authentication in PgBouncer
Description
Improper authentication in PgBouncer 1.17.0 through 1.26.0 allows a remote attacker who knows the password of a user listed in auth_file to log in as any other user that authenticates using SCRAM, including PgBouncer admin users and backend superusers. A second StartupMessage sent during SCRAM authentication against a non-existent database is not rejected and switches the user being logged in as, while the SCRAM exchange is still verified against the keys of the first user.
INFO
Published Date :
Oct. 14, 2026, 6:17 p.m.
Last Modified :
Oct. 14, 2026, 6:17 p.m.
Remotely Exploit :
No
Source :
f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update PgBouncer to a patched version.
- Apply vendor-provided security updates.
- Restrict access to authentication files.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-107350.
| URL | Resource |
|---|---|
| https://www.pgbouncer.org/changelog.html |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-107350 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-107350
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-107350 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-107350 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
Oct. 14, 2026
Action Type Old Value New Value Added Description Improper authentication in PgBouncer 1.17.0 through 1.26.0 allows a remote attacker who knows the password of a user listed in auth_file to log in as any other user that authenticates using SCRAM, including PgBouncer admin users and backend superusers. A second StartupMessage sent during SCRAM authentication against a non-existent database is not rejected and switches the user being logged in as, while the SCRAM exchange is still verified against the keys of the first user. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-287 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/107xxx/CVE-2026-107350.json">CVE-2026-107350</a> Added Reference https://www.pgbouncer.org/changelog.html