Critical severity · published May 9, 2026
CVE-2026-6665
PgBouncer buffer overflow in SCRAM
9.8
CVSS
0.4%
EPSS
No
On KEV
Description
The SCRAM code in PgBouncer before 1.25.2 did not check the return value of strlcat() correctly when building the contents of the SCRAM client-final-message. A malicious backend that sends a SCRAM server-final-message with a long nonce can trigger a stack overflow.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PG
PgBouncer ·
before 1.25.2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6665
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-6665
Release Notes
https://www.pgbouncer.org/changelog.html#pgbouncer-125x
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