What is the CVSS score of CVE-2026-27125?

CVE-2026-27125 has a CVSS 3.1 base score of 6.8 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N. EPSS exploitation probability: 0.1%.

How to fix or mitigate CVE-2026-27125?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Vendor patch is available.

Svelte CVE-2026-27125

MEDIUM

Improperly Controlled Modification of Dynamically-Determined Object Attributes (CWE-915)

2026-02-20 security-advisories@github.com

GHSA-crpf-4hrx-3jrp

Code Injection Red Hat Svelte

6.8

CVSS 3.1 · GitHub Advisory

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Vulnerability Assessment

Weakness	CWE CWE-915 OWASP Top 10:2025 A08:2025 - Software or Data Integrity Failures ASVS 5.0 V4 - API and Web Service Object attribute protection
Impact	CVSS 6.8 (MEDIUM). Attack vector: Network. Complexity: High. Privileges required: Low. User interaction: None.
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 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Svelte versions prior to 5.51.5 improperly enumerate prototype chain properties during server-side rendering attribute spreading, allowing polluted Object.prototype properties to inject unexpected attributes into SSR output or cause rendering errors. This vulnerability affects applications using SSR where the prototype chain has been previously manipulated, though client-side rendering is unaffected. The issue requires prototype pollution as a precondition but can lead to information disclosure or denial of service in vulnerable SSR environments.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 22:04 CVSS 6.8

Svelte versions up to 5.51.5 is affected by improperly controlled modification of dynamically-determined object attributes (CVSS 6.8).

RemediationAI

A vendor patch is available — apply it immediately. Fixed in version 5.51.5.. Restrict network access to the affected service where possible.

Affected Packages

npm svelte fix: 5.51.5

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

This vulnerability (CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes) affects Svelte. svelte performance oriented web framework. Prior to 5.51.5, in server-side rendering, attribute spreading on elements (e.g. <div {...attrs}>) enumerates inherited properties from the object's prototype chain rather than only own properties. In environments where Object.prototype has already been polluted — a precondition outside of Svelte's control — this can cause unexpected attributes to appear in SSR output or cause SSR to throw errors. Client-side rendering is not affected. This vulnerabilit

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

GitHub Advisory PRIMARY 6.8 MEDIUM

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

Red Hat 5.6 MEDIUM

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Patch released

Feb 23, 2026 - 20:52 nvd

Patch available

CVE Published

Feb 20, 2026 - 23:16 nvd

MEDIUM 6.8

DescriptionGitHub Advisory

svelte performance oriented web framework. Prior to 5.51.5, in server-side rendering, attribute spreading on elements (e.g. <div {...attrs}>) enumerates inherited properties from the object's prototype chain rather than only own properties. In environments where Object.prototype has already been polluted - a precondition outside of Svelte's control - this can cause unexpected attributes to appear in SSR output or cause SSR to throw errors. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.

Executive ViewAI

Why It Matters

CVE-2026-27125 presents notable security risk rated CVSS 6.8. Exploitation could compromise the security of affected deployments. A patch is available and should be applied during regular vulnerability management.

Business Impact: Moderate

Compensating Controls

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

Threat Intelligence Overview

EPSS Score

0.1%

Top 78% exploitable

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS 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 0.1%

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

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +34

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.