PostgreSQL PgBouncer up to 1.25.2 Packet Buffer Growth Logic integer overflow

Summaryinfo

A vulnerability classified as problematic has been found in PostgreSQL PgBouncer up to 1.25.2. This affects an unknown part of the component Packet Buffer Growth Logic. The manipulation leads to integer overflow. This vulnerability is uniquely identified as CVE-2026-6668. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in PostgreSQL PgBouncer up to 1.25.2 and classified as problematic. This issue affects some unknown processing of the component Packet Buffer Growth Logic. The manipulation with an unknown input leads to a integer overflow vulnerability. Using CWE to declare the problem leads to CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. Impacted is availability. The summary by CVE is:

Integer overflow in the packet buffer growth logic in PgBouncer through 1.25.2 allows an unauthenticated remote attacker to cause a denial of service. Sufficiently large input makes the buffer size computation overflow, leaving the growth loop unable to terminate. Because PgBouncer serves all clients from a single process, this saturates a CPU core and stalls every pooled connection until the process is killed. Both unauthenticated and authenticated code paths can reach the overflow.

The advisory is shared at pgbouncer.org. The identification of this vulnerability is CVE-2026-6668 since 04/20/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/24/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3529). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Open Source PgBouncer

Productinfo

Type

• Database Software

Vendor

• PostgreSQL

Name

• PgBouncer

Version

• 1.25.0
• 1.25.1
• 1.25.2

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion