What is the CVSS score of CVE-2025-66382?

CVE-2025-66382 has a CVSS 3.1 base score of 5.5 (Medium). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

How to fix or mitigate CVE-2025-66382?

During next maintenance window: Apply vendor patches when convenient. Monitor vendor channels for updates.

Libexpat CVE-2025-66382

MEDIUM

Inefficient Algorithmic Complexity (CWE-407)

2025-11-28 cve@mitre.org

Information Disclosure Red Hat Libexpat Libexpat Project

5.5

CVSS 3.1 · NVD

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Vulnerability Assessment

Weakness	CWE CWE-407 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V2 - Validation and Business Logic Algorithmic complexity limits
Impact	CVSS score of 2.9 (LOW). Attack characteristics: local attack vector, high complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 0.01%.
Exploit ScenarioDerived	Successful exploitation could compromise the low-severity affected system.

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 – Mar 28, 2026

In libexpat through 2.7.3, a crafted file with an approximate size of 2 MiB can lead to dozens of seconds of processing time. Rated low severity (CVSS 2.9), this vulnerability is no authentication required. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

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

Technical ContextAI · show details

This vulnerability is classified under CWE-407. In libexpat through 2.7.3, a crafted file with an approximate size of 2 MiB can lead to dozens of seconds of processing time. Affected products include: Libexpat Project Libexpat. Version information: through 2.7.3.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 5.5 MEDIUM

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

Red Hat 2.9 LOW

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Severity Changed

Oct 19, 2026 - 13:23 NVD

LOW MEDIUM

CVSS changed

Oct 19, 2026 - 13:23 NVD

2.9 (LOW) 5.5 (MEDIUM)

CVE Published

Nov 28, 2025 - 07:15 nvd

LOW 2.9

DescriptionNVD

In libexpat through 2.7.3, a crafted file with an approximate size of 2 MiB can lead to dozens of seconds of processing time.

Executive ViewAI

Why It Matters

CVE-2025-66382 is a low-severity vulnerability in libexpat (CVSS 2.9). The limited severity suggests constrained impact, typically requiring specific conditions or local access for exploitation. Apply vendor updates when available as part of routine maintenance.

Business Impact: Low

Compensating Controls

Apply vendor patch during routine maintenance. Standard security controls provide adequate interim protection.

Threat Intelligence Overview

EPSS Score

0.0%

Top 99% exploitable

Threat Intel

1 source

Data Quality

5 sources

Confidence: Medium

NVD

CVE.org

EPSS CISA Vendor

GitHub

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 Yes

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

Defer

Exploitation· derived

None

System Exposure· derived

Small

Automatable· derived

Human Impact

Low

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +28

PoC: 0

Weaponized: 0

Threat intel: +10

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.