VDB-347952 · CVE-2026-27902 · GHSA-qgvg-pr8v-6rr3

sveltejs svelte up to 5.53.4 cross site scripting

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.2	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as problematic has been found in sveltejs svelte up to 5.53.4. Affected by this vulnerability is an unknown functionality. The manipulation results in cross site scripting. This vulnerability is reported as CVE-2026-27902. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, was found in sveltejs svelte up to 5.53.4. Affected is an unknown part. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

Svelte performance oriented web framework. Prior to version 5.53.5, errors from `transformError` were not correctly escaped prior to being embedded in the HTML output, causing potential HTML injection and XSS if attacker-controlled content is returned from `transformError`. Version 5.53.5 fixes the issue.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-27902 since 02/24/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 5.53.5 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 0298e979371bb583855c9810db79a70a551d22b9 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

sveltejs

Name

svelte

Version

License

open-source

Website

Product: https://github.com/sveltejs/svelte/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.2
VulDB Meta Temp Score: 4.2

VulDB Base Score: 3.1
VulDB Temp Score: 3.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.4
NVD Vector: 🔒

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: svelte 5.53.5
Patch: 0298e979371bb583855c9810db79a70a551d22b9

Timelineinfo

02/24/2026 CVE reserved
02/26/2026 +2 days Advisory disclosed
02/26/2026 +0 days VulDB entry created
03/05/2026 +7 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-qgvg-pr8v-6rr3
Status: Confirmed

CVE: CVE-2026-27902 (🔒)
GCVE (CVE): GCVE-0-2026-27902
GCVE (VulDB): GCVE-100-347952

Entryinfo

Created: 02/26/2026 07:29
Updated: 03/05/2026 16:57
Changes: 02/26/2026 07:29 (70), 03/05/2026 16:57 (12)
Complete: 🔍
Cache ID: 216::103