Vulnerability-Lookup

GHSA-R96C-7W9V-WRC8

Vulnerability from github – Published: 2026-09-23 18:31 – Updated: 2026-09-23 18:31

Details

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.

Severity

7.5 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-6668"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-23T17:17:16Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-r96c-7w9v-wrc8",
  "modified": "2026-09-23T18:31:56Z",
  "published": "2026-09-23T18:31:56Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6668"
    },
    {
      "type": "WEB",
      "url": "https://www.pgbouncer.org/changelog.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-6668 (GCVE-0-2026-6668)

Vulnerability from cvelistv5 – Published: 2026-09-23 16:04 – Updated: 2026-09-23 16:46

Title

Integer overflow causes an infinite loop in packet buffer growth in PgBouncer

Summary

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-23 16:33 UTC

CWE

CWE-190 - Integer Overflow or Wraparound
CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Assigner

PostgreSQL redhat root

References

1 reference

URL	Tags
https://www.pgbouncer.org/changelog.html

Impacted products

1 product

Vendor	Product	Version
n/a	PgBouncer	Affected: 0 , ≤ 1.25.2 (semver)

Credits

Thanks to @var77 for finding and reporting this issue.

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-6668",
                "options": [
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                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-23T16:33:22.320321Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-23T16:46:13.834Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
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    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "PgBouncer",
          "vendor": "n/a",
          "versions": [
            {
              "lessThanOrEqual": "1.25.2",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "max_packet_size is left at its default of 2147483647 (default configuration), which is what permits a packet large enough to reach the overflow. No other non-default configuration is required."
        }
      ],
      "credits": [
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          "lang": "en",
          "type": "finder",
          "value": "Thanks to @var77 for finding and reporting this issue."
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          "lang": "en",
          "value": "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."
        }
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      "metrics": [
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
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        }
      ],
      "title": "Integer overflow causes an infinite loop in packet buffer growth in PgBouncer",
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          "lang": "en",
          "value": "Set max_packet_size well below 1073741824 so that no single packet can grow a packet buffer past the overflow threshold"
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    "dateReserved": "2026-04-20T12:25:46.351Z",
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    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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GHSA-R96C-7W9V-WRC8

CVE-2026-6668 (GCVE-0-2026-6668)

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