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IBM Db2 EUVDEUVD-2026-32280

| CVE-2026-3676 MEDIUM
Improper Validation of Specified Quantity in Input (CWE-1284)
2026-05-27 psirt@us.ibm.com GHSA-p4qj-fgm6-87w7
6.5
CVSS 3.1 · Vendor: us
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Obtain low-privilege DB credentials
  2. Delivery
    Connect to Db2 listener over network
  3. Exploit
    Submit crafted query with malformed special elements
  4. Execution
    Trigger CWE-1284 validation failure in Fenced environment
  5. Persist
    Crash Fenced process
  6. Impact
    Deny service to APM data query operations

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V2 - Validation and Business Logic Input size validation
Exploitation Conditions

Exploitation requires a valid, low-privilege authenticated database account (CVSS PR:L confirmed). The vulnerability is specific to the Fenced environment query logic within the IBM Db2 component - exploitation is conditional on the attacker being able to submit data queries that reach this Fenced execution context, which typically means access to execute UDFs or stored procedures running in fenced mode. The attack is network-accessible (AV:N) with low complexity (AC:L) and requires no user interaction. Limiting conditions include: the attacker must hold valid database credentials; the impact is availability-only with no data exfiltration possible through this vector; and the scope is unchanged (S:U), suggesting the DoS may be contained to the Fenced process rather than cascading to the full Db2 instance or host OS. Default Db2 installations run UDFs in fenced mode, so this is not a non-default configuration requirement.

Impact

The CVSS vector (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) indicates network-reachable exploitation requiring only low-privilege authentication, with no complexity barrier and full availability impact. This aligns with a realistic denial-of-service scenario: any authenticated database user could potentially crash the Fenced process or degrade service. However, real-world priority is moderated by several factors: exploitation requires valid credentials (PR:L), there is no confidentiality or integrity impact, the vulnerability is not listed in CISA KEV, and no public exploit code has been identified at time of analysis. The EPSS score is not provided in the source data, so exploitation probability cannot be quantified. For organizations running IBM Cloud APM in multi-tenant or shared environments where database credentials are broadly distributed, the risk is elevated because the authentication barrier is lower in practice. For tightly controlled single-tenant deployments, risk is considerably lower. The Fenced environment context suggests the DoS may be limited to the fenced process rather than a full Db2 instance crash, but this scope limitation is inferred from architecture and not explicitly confirmed by the advisory.

Exploit ScenarioDerived

An authenticated low-privilege user with database credentials - such as an application service account or an internal analyst with read-only access - submits a crafted query containing malformed or boundary-violating special elements to the Db2 Fenced environment. The query bypasses input validation in the query logic, causing the Fenced process to crash or enter an unrecoverable state, resulting in denial of service for operations relying on Fenced UDFs or the APM monitoring data pipeline. No public proof-of-concept code has been identified at time of analysis.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – May 27, 2026

Authenticated denial-of-service in IBM Db2 for Linux, UNIX, and Windows allows a low-privileged network user to crash database availability by submitting specially crafted data queries against the Fenced environment. The vulnerability affects IBM Cloud APM Base Private 8.1.4 and Advanced Private 8.1.4, which bundle Db2 as a backend component. No public exploit has been identified at time of analysis, and the CVSS score of 6.5 reflects meaningful but bounded risk due to the authentication prerequisite.

RemediationAI

The primary remediation is to apply the IBM-issued fix referenced in vendor advisory https://www.ibm.com/support/pages/node/7273649. The EUVD affected version notation 'Cloud APM, Base Private 8.1.4 ≤ Interim Fix 021' implies that a fix exists beyond Interim Fix 021 (i.e., Interim Fix 022 or later), but an exact patched version number is not independently confirmed from the available source data - consult the IBM advisory directly to obtain the precise fix package. As a compensating control prior to patching, restrict database access to the minimum required set of authenticated users, particularly limiting which accounts can submit arbitrary queries against the Fenced environment. Disabling or restricting UDF execution in the Fenced environment may reduce exposure but carries functional trade-offs for applications relying on fenced UDFs or stored procedures. Network-layer controls restricting Db2 listener port access (default TCP 50000) to trusted application hosts can reduce the attack surface without application impact.

Affected VersionsENISA

Cloud APM, Advanced Private 8.1.4
Cloud APM, Base Private 8.1.4 ≤) Interim Fix 021

Affected Packages

euvd cloud_apm_advanced_private no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

IBM Db2's Fenced environment is an isolated process space used to execute user-defined functions (UDFs) and stored procedures in a sandboxed context, separating them from the core database engine for stability and security. The root cause is CWE-1284 (Improper Validation of Specified Quantity in Input), meaning the query processing logic in the Fenced environment fails to properly neutralize or validate special elements in input data - likely boundary values, escape sequences, or malformed quantity parameters - that can trigger resource exhaustion or process termination. Affected products per the EUVD entry are IBM Cloud APM Base Private 8.1.4 (up to and including Interim Fix 021) and IBM Cloud APM Advanced Private 8.1.4, both of which embed Db2 for Linux, UNIX, and Windows including DB2 Connect Server.

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Severity by source

Vendor (us) PRIMARY 6.5 MEDIUM
AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Primary rating from Vendor (us) · only source for this CVE.

CVSS VectorVendor: us

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionCVE.org

IBM Cloud APM, Base Private 8.1.4 and IBM Cloud APM, Advanced Private 8.1.4 IBM Db2 for Linux, UNIX and Windows (includes DB2 Connect Server) could allow an authenticated user to cause a denial of service due to improper neutralization of special elements in the data query logic of the Fenced environment.

Threat Intelligence Overview

EPSS Score
0.0%
Top 86% exploitable
Data Quality
4 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.0%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

32
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +32
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

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