What is the CVSS score of CVE-2026-1527?

CVE-2026-1527 has a CVSS 3.1 base score of 4.6 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

How to fix or mitigate CVE-2026-1527?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Redis CVE-2026-1527

Q: Which versions of Redis are affected by CVE-2026-1527?

CVE-2026-1527 presents moderate security risk rated CVSS 4.6. Exploitation could compromise the security of affected deployments.. A patch is available.

EUVD-2026-11701 MEDIUM

Improper Neutralization of CRLF Sequences ('CRLF Injection') (CWE-93)

2026-03-12 ce714d77-add3-4f53-aff5-83d477b104bb

GHSA-4992-7rv2-5pvq

Node.js Redis Code Injection Red Hat Elastic Undici Suse

4.6

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-93 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V1 - Encoding and Sanitization CRLF sequence sanitization
Impact	CVSS 4.6 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: Low. User interaction: Required.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to compromise the affected system.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

CRLF injection in undici's HTTP upgrade handling allows authenticated attackers to inject arbitrary headers and perform request smuggling attacks against backend services like Redis and Elasticsearch when user input is passed unsanitized to the upgrade option. The vulnerability stems from insufficient validation of the upgrade parameter before writing to the socket, enabling attackers to terminate HTTP requests prematurely and route malicious data to non-HTTP protocols. This requires prior authentication and user interaction, with no patch currently available.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 22:55 CVSS 4.6

ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to:

Inject arbitrary HTTP headers
Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)

The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters:

// lib/dispatcher/client-h1.js:1121 if (upgrade) { header += connection: upgrade\r\nupgrade: ${upgrade}\r\n } [CVSS 4.6 MEDIUM]

RemediationAI

Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.

Affected VersionsENISA

undici < 6.24.0; 7.0.0 < 7.24.0

Affected Packages

npm undici fix: 6.24.0, 7.24.0

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in npm

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

Technical ContextAI · show details

ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to:

Inject arbitrary HTTP headers
Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)

The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters:

// lib/dispatcher/client-h1.js:1121 if (upgrade) { heade

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 4.6 MEDIUM

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

SUSE MEDIUM

Red Hat 6.5 MEDIUM

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

CVE Published

Mar 12, 2026 - 21:16 nvd

MEDIUM 4.6

DescriptionCVE.org

ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to:

Inject arbitrary HTTP headers
Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)

The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters:

// lib/dispatcher/client-h1.js:1121 if (upgrade) { header += connection: upgrade\r\nupgrade: ${upgrade}\r\n }

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

28 npm packages depend on undici (16 direct, 23 indirect)

Ecosystem-wide dependent count for version 7.0.0.

Executive ViewAI

Why It Matters

CVE-2026-1527 presents moderate security risk rated CVSS 4.6. Exploitation could compromise the security of affected deployments. Organizations should apply vendor updates when available and monitor for exploitation.

Business Impact: Low

Compensating Controls

Apply vendor patch. If patching is delayed: restrict network access and enable monitoring.

Threat Intelligence Overview

EPSS Score

0.0%

Top 92% exploitable

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS Vendor

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 MEDIUM

CISA KEV No

Public POC No

EPSS 0.0%

Patch available Yes

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

Defer

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Human Impact

Low

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +23

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Code Injection CRITICAL

Code injection occurs when an application accepts user input and passes it directly into a language interpreter or evaluator without proper sanitization.