CVE-2026-6665

critical

Published 2026-05-09 · Modified 2026-05-14

CVSS v3

9.8

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

CVSS v2

—

VIR risk

9.8

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.

Predictions

Exploit likelihood

97%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-6665

vendor Authored 2026-05-27

Vendor advisory: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 — https://www.pgbouncer.org/changelog.html#pgbouncer-125x

OS impact

OS	Version	Status	Fixed in
debian	bookworm	affected
debian	bullseye	affected
debian	forky	fixed	`1.25.2-1`
debian	sid	fixed	`1.25.2-1`
debian	trixie	fixed	`1.24.1-1+deb13u2`

Application impact

Vendor	Product	Versions	Fixed
pgbouncer	pgbouncer	`{"endExcluding":"1.25.2"}`	`1.25.2`

References

CWEs

CWE-121

Verify integrity in audit chain (admin only). AS-IS.