What is the CVSS score of CVE-2026-27171?

CVE-2026-27171 has a contested CVSS base score of 2.9 from a third party (e.g. CISA-ADP), while the vendor rates it Low. vuln.today uses the vendor rating as authoritative.

Is there a public PoC exploit available for CVE-2026-27171?

Yes, a public proof-of-concept exploit is available for CVE-2026-27171. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-27171?

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

Zlib CVE-2026-27171

LOW

Improper Validation of Specified Quantity in Input (CWE-1284)

2026-02-18 cve@mitre.org

Information Disclosure Zlib

Low

Disputed · 2.9 NVD

View

Vulnerability Assessment

Weakness	CWE CWE-1284 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V14 - Configuration Dependency management, component inventory
Impact	CVSS 2.9 (LOW). Attack vector: Local. Complexity: High. Privileges required: None. User interaction: None. Public exploit/POC available.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to compromise the affected system.

Monitor Track and reassess. Why: LOW severity (CVSS 0.1-3.9).

No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do right shifts within a loop that has no termination condition. [CVSS 2.9 LOW]

RemediationAI

Monitor vendor advisories for a patch.

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

Affects Zlib. zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do right shifts within a loop that has no termination condition.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Sources disagree (Low–High)

NVD PRIMARY 2.9 LOW

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

ENISA EUVD HIGH

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Lifecycle Timeline

PoC Detected

Mar 25, 2026 - 21:27 vuln.today

Public exploit code

CVE Published

Feb 18, 2026 - 04:16 nvd

LOW 2.9

DescriptionCVE.org

zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do right shifts within a loop that has no termination condition.

Executive ViewAI

Why It Matters

CVE-2026-27171 is a low-severity vulnerability in zlib before 1.3.2 (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 100% exploitable

Threat Intel

1 source

Exploit

POC

Public exploit code exists

Data Quality

6 sources

Confidence: High

NVD

CVE.org

EPSS NCSC-NL

GitHub

VulDB

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 LOW

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

LOW severity (CVSS 0.1-3.9)

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

Poc

System Exposure· derived

Small

Automatable· derived

Human Impact

Low

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +14

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: +5

Attack Technique

Information Disclosure MEDIUM

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