CVE-2026-6669
📛 CVE Title
Unbounded SCRAM iteration count causes CPU exhaustion in PgBouncer
Description
Missing upper bound on the key derivation iteration count accepted during SCRAM authentication to a backend server in PgBouncer through 1.25.2 allows a malicious or compromised PostgreSQL backend to cause uncontrolled CPU consumption in PgBouncer. The resulting key derivation cannot be interrupted in frontend builds such as PgBouncer. Because PgBouncer serves all clients from a single process, one backend can in this way stop it from serving traffic for every other database and client it is pooling, so the failure of a single backend is not contained.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- PostgreSQL
- CVSS severity
- MEDIUM
- CVSS score
- 5.9 / 10
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H- Effective score
- 5.9 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-400 - Reserved
- 2026-04-20
- Published
- 2026-09-23 16:04 UTC
- Last updated
- 2026-09-23 16:46 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/6xxx/CVE-2026-6669.json
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-09-23 17:17:16 UTC
- NVD last modified
- 2026-09-23 19:40:10 UTC
- NVD CVSS v3.1
- 5.9 / 10 MEDIUM source: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
- NVD CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H- Exploitability subscore
- 2.2 / 10
- Impact subscore
- 3.6 / 10
NVD / KEV / EPSS data refreshed 2026-09-24 04:36 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-85364 - Assigner
- PostgreSQL
- Published
- Sep 23, 2026, 4:04:47 PM
- Updated
- Sep 23, 2026, 4:46:13 PM
- EUVD base score (CVSS 3.1)
-
5.9 / 10
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - EUVD-reported EPSS
- 0.0000
- Vendors
- n/a
- Products
-
PgBouncer (0 ≤1.25.2)
- Aliases
-
GHSA-58j7-v2vx-r29w
ENISA description: Missing upper bound on the key derivation iteration count accepted during SCRAM authentication to a backend server in PgBouncer through 1.25.2 allows a malicious or compromised PostgreSQL backend to cause uncontrolled CPU consumption in PgBouncer. The resulting key derivation cannot be interrupted in frontend builds such as PgBouncer. Because PgBouncer serves all clients from a single process, one backend can in this way stop it from serving traffic for every other database and client it is pooling, so the failure of a single backend is not contained.
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| n/a | PgBouncer |
0 (affected)
|
— |
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
Web references (0)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
No web references attached yet.
NVD-tagged references (1)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://www.pgbouncer.org/changelog.html f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
Remediations (10)
-
web:app.opencve.io
Remediation No vendor fix or workaround currently provided. OpenCVE Recommended Actions Download and install the latest Windows cumulative update that fixes CVE‑2026‑69669 from the Microsoft Security Update Guide. Reboot the affected machines to load the updated kernel and ensure the vulnerability is removed.
2026-09-24 11:51 UTC -
web:arcticwolf.com
Threat Summary On June 9, 2026 , Microsoft released its regular Patch Tuesday security update, fixing 206 vulnerabilities (with 39 rated Critical) affecting a broad spectrum of Microsoft products including Windows kernel, Hyper-V, Remote Desktop Client, Kerberos, DHCP, BitLocker, HTTP.sys, Exchange Server, and Office. This is the largest number of vulnerabilities ever disclosed in a single ...
2026-09-24 11:51 UTC -
web:msrc.microsoft.com
Security Update Guide - Microsoft Security Response Center
2026-09-24 11:51 UTC -
web:senserva.com
Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.
2026-09-24 11:51 UTC -
web:support.microsoft.com
This out-of-band (OOB) update for Windows 11, version 25H2 and Windows 11, version 24H2 (KB5121768) is cumulative. It includes all improvements from previous security and non-security updates, along with an additional fix . Improvements This OOB update includes the following improvement: [System Performance] This update addresses an issue affecting a limited number of devices with an Intel ...
2026-09-24 11:51 UTC -
web:support.microsoft.com
This Hotpatch update for Windows 11, version 25H2 and 24H2 (KB5079420), improves functionality, performance, and reliability. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of ...
2026-09-24 11:51 UTC -
web:windowsreport.com
Microsoft's September 2026 Patch Tuesday fixes a record 966 security vulnerabilities, including two zero-days that attackers are actively exploiting. Microsoft has released Patch Tuesday updates for Windows 11 alongside Windows 10 KB5122878, delivering what appears to be the company's largest Patch Tuesday security release to date.
2026-09-24 11:51 UTC -
web:www.crowdstrike.com
Microsoft patches 206 vulnerabilities in June 2026 Patch Tuesday, including three publicly disclosed zero-days.
2026-09-24 11:51 UTC -
web:www.ivanti.com
June 2026 Patch Tuesday marks a new phase of the Patch Apocalypse, with Microsoft, Chrome and Adobe resolving record-breaking CVE counts.
2026-09-24 11:51 UTC -
web:www.splashtop.com
Microsoft's June 2026 Patch Tuesday fixes 206 flaws, including 3 zero-days and Critical risks across Windows, Azure, HTTP.sys, and more.
2026-09-24 11:51 UTC
AI Forensic Analysis
Only Available for Registered Users. Sign in to view.
Raw JSON
The full cvelistV5 record. Download as CVE-2026-6669.json.
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-6669",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-23T16:33:29.069636Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-09-23T16:46:13.708Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "PgBouncer",
"vendor": "n/a",
"versions": [
{
"lessThanOrEqual": "1.25.2",
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"configurations": [
{
"lang": "en",
"value": "PgBouncer authenticates to a backend PostgreSQL server using SCRAM"
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Thanks to @HarutoKimura for finding and reporting this issue."
}
],
"descriptions": [
{
"lang": "en",
"value": "Missing upper bound on the key derivation iteration count accepted during SCRAM authentication to a backend server in PgBouncer through 1.25.2 allows a malicious or compromised PostgreSQL backend to cause uncontrolled CPU consumption in PgBouncer. The resulting key derivation cannot be interrupted in frontend builds such as PgBouncer. Because PgBouncer serves all clients from a single process, one backend can in this way stop it from serving traffic for every other database and client it is pooling, so the failure of a single backend is not contained."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.9,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-400",
"description": "Uncontrolled Resource Consumption",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-23T16:04:47.824Z",
"orgId": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
"shortName": "PostgreSQL"
},
"references": [
{
"url": "https://www.pgbouncer.org/changelog.html"
}
],
"title": "Unbounded SCRAM iteration count causes CPU exhaustion in PgBouncer"
}
},
"cveMetadata": {
"assignerOrgId": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
"assignerShortName": "PostgreSQL",
"cveId": "CVE-2026-6669",
"datePublished": "2026-09-23T16:04:47.824Z",
"dateReserved": "2026-04-20T12:25:47.129Z",
"dateUpdated": "2026-09-23T16:46:13.708Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}