How severe is CVE-2026-6664?

CVE-2026-6664 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-6664 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-6664?

CVE-2026-6664 affects Pgbouncer. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-6664?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-6664 have an EU (EUVD) identifier?

Yes. CVE-2026-6664 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28876.

When was CVE-2026-6664 published?

CVE-2026-6664 was published on 2026-05-09 and last updated on 2026-06-17.

CVE-2026-6664

CVE-2026-6664 is a high-severity vulnerability in Pgbouncer with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-28876
Weakness: CWE-190
Affected product: Pgbouncer
Published: 2026-05-09
Last modified: 2026-06-17

Description

An integer overflow in network packet parsing code in PgBouncer before 1.25.2 bypasses a boundary check and can lead to a crash. An unauthenticated remote attacker can crash PgBouncer with a malformed SCRAM authentication packet.

Frequently asked questions

What is CVE-2026-6664?: An integer overflow in network packet parsing code in PgBouncer before 1.25.2 bypasses a boundary check and can lead to a crash. An unauthenticated remote attacker can crash PgBouncer with a malformed SCRAM authentication packet.
How severe is CVE-2026-6664?: CVE-2026-6664 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-6664 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-6664?: CVE-2026-6664 affects Pgbouncer. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-6664?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-6664 have an EU (EUVD) identifier?: Yes. CVE-2026-6664 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28876.
When was CVE-2026-6664 published?: CVE-2026-6664 was published on 2026-05-09 and last updated on 2026-06-17.

References

https://www.pgbouncer.org/changelog.html#pgbouncer-125x

Affected products (1)

cpe:2.3:a:pgbouncer:pgbouncer:*:*:*:*:*:*:*:*

More vulnerabilities in Pgbouncer

CVE-2026-6665 — High (CVSS 8.1): The SCRAM code in PgBouncer before 1.25.2 did not check the return value of strlcat() correctly when building the…
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CVE-2021-3935 — High (CVSS 8.1): When PgBouncer is configured to use "cert" authentication, a man-in-the-middle attacker can inject arbitrary SQL…
CVE-2015-6817 — High (CVSS 8.1): PgBouncer 1.6.x before 1.6.1, when configured with auth_user, allows remote attackers to gain login access as auth_user…
CVE-2025-12819 — High (CVSS 7.5): Untrusted search path in auth_query connection handler in PgBouncer before 1.25.1 allows an unauthenticated attacker to…
CVE-2015-4054 — High (CVSS 7.5): PgBouncer before 1.5.5 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) by…

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Other CWE-190 (Integer Overflow or Wraparound) vulnerabilities

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CVE-2015-5108 — Critical (CVSS 10.0): Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC…
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