Unbounded SCRAM iteration count causes CPU exhaustion in PgBouncer (CVE-2026-6669) | HOL Guard CVE

Medium · CVSS 5.9CVE-2026-6669

Unbounded SCRAM iteration count causes CPU exhaustion in PgBouncer

Answer in brief

CVE-2026-6669 records a Medium severity (CVSS 5.9) vulnerability in Unbounded SCRAM iteration count causes CPU exhaustion in PgBouncer. The current sources do not mark it as known exploited. The current feed maps n/a/PgBouncer (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 23, 2026Updated Sep 23, 2026Source checked Sep 23, 2026First seen by HOL Sep 23, 2026Material review Sep 23, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.9
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps n/a/PgBouncer (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
n/a/PgBouncergeneric	>=0 <=1.25.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for n/a/PgBouncer.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 23, 2026

Sources and claim methodology

Source referencepgbouncer.org

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.