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CVE Record

CVE-2026-42198: pgjdbc: Unbounded PBKDF2 iterations in SCRAM authentication allows CPU exhaustion DoS

pgjdbc is an open source postgresql JDBC Driver. From version 42.2.0 to before version 42.7.11, pgjdbc is vulnerable to a client-side denial of service during SCRAM-SHA-256 authentication. A malicious server can instruct the driver to perform SCRAM authentication with a very large iteration count. With a large enough value, the client spends an unbounded amount of CPU time inside PBKDF2 before authentication can fail. A single attempt ties up a CPU core. Repeated or concurrent attempts exhaust client CPU and can wedge connection pools. In affected versions, loginTimeout did not fully mitigate this problem. When loginTimeout expired, the caller could stop waiting, but the worker thread performing the connection attempt could continue running and burning CPU inside the SCRAM PBKDF2 computation. This issue has been patched in version 42.7.11.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

Affected Java applications using pgjdbc can be forced by a malicious PostgreSQL-compatible server to spend excessive CPU during login. One connection attempt can occupy a CPU core, and repeated attempts can exhaust client CPU or wedge connection pools. The issue is fixed in pgjdbc 42.7.11.

Executive priority

Treat this as a high-priority availability fix for Java applications that depend on PostgreSQL. The main business risk is service degradation from CPU exhaustion, not data theft. Prioritize critical services, shared connection pools, and systems with externally influenced database routing.

Technical view

pgjdbc versions 42.2.0 through before 42.7.11 perform SCRAM-SHA-256 authentication without bounding the PBKDF2 iteration count supplied by the server. A hostile server can choose an extremely large count, causing client-side CPU exhaustion before authentication fails. loginTimeout did not stop the underlying worker thread from continuing the computation.

Likely exposure

Exposure is most likely in Java services using pgjdbc 42.2.0 to before 42.7.11, especially where connection strings can reach untrusted, compromised, or misdirected PostgreSQL endpoints. Internet-facing applications are indirectly exposed if attackers can influence database destinations, DNS, configuration, or connection retry behavior.

Exploitation context

The source bundle reports no KEV listing and provides no evidence of active exploitation. Exploitation requires a malicious or controlled server endpoint involved in SCRAM authentication. The impact is availability only: CPU exhaustion on client systems and possible connection pool wedging.

Researcher notes

Key detail: loginTimeout was not a complete control because worker threads could continue burning CPU after callers stopped waiting. Validate actual runtime dependency resolution, not only declared versions, because shaded or bundled JDBC drivers may differ from manifest expectations.

Mitigation direction

  • Upgrade pgjdbc to version 42.7.11 or later.
  • Apply relevant vendor advisories, including Red Hat errata where applicable.
  • Inventory applications and containers that bundle vulnerable pgjdbc versions.
  • Restrict database connectivity to trusted PostgreSQL endpoints.
  • Review connection retry behavior for excessive repeated authentication attempts.

Validation and detection

  • Check dependency manifests, SBOMs, and packaged JARs for pgjdbc versions.
  • Confirm production runtimes load pgjdbc 42.7.11 or later.
  • Identify services using SCRAM-SHA-256 PostgreSQL authentication.
  • Review connection pool metrics for stuck or CPU-heavy login attempts.
  • Verify Red Hat affected packages against applicable errata.
Prepared
Confidence
high
Sources
10

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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cwe · low confidence lookup

CWE-770: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-42198 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
10Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6GitHub_M
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-42198Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPjdbc.postgresql.org: pgjdbc: Client-side Denial of Service via malicious SCRAM-SHA-256 authentication
other:Red Hat severity ratingcvssV3_1
  • 2026-04-29T17:00:59.186Z: Reported to Red Hat.
  • 2026-04-29T15:58:49.174Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
pgjdbcpgjdbc>= 42.2.0, < 42.7.11Listed
Weakness

CWE details

CWE-770

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CWE-770 · source CWE mapping

Allocation of Resources Without Limits or Throttling

Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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