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Laravel CVE-2021-43808

MEDIUM
Cross-site Scripting (XSS) (CWE-79)
2021-12-08 security-advisories@github.com
6.1
CVSS 3.1 · NVD
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Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK

2 techniques across 2 tactics: Initial Access, Execution

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 6.1 (MEDIUM). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. Public proof-of-concept exploit code is available.

Exploit ScenarioDerived

A remote attacker could inject malicious scripts into web pages viewed by other users by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.8% exploitation probability (EPSS)

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AnalysisAI

Laravel is a web application framework. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.

Affected Packages

composer illuminate/view fix: 6.20.42, 7.30.6, 8.75.0
composer laravel/framework fix: 6.20.42, 7.30.6, 8.75.0

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 2 packages in composer

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 as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. Laravel is a web application framework. Laravel prior to versions 8.75.0, 7.30.6, and 6.20.42 contain a possible cross-site scripting (XSS) vulnerability in the Blade templating engine. A broken HTML element may be clicked and the user taken to another location in their browser due to XSS. This is due to the user being able to guess the parent placeholder SHA-1 hash by trying common names of sections. If the parent template contains an exploitable HTML structure an XSS vulnerability can be exposed. This vulnerability has been patched in versions 8.75.0, 7.30.6, and 6.20.42 by determining the parent placeholder at runtime and using a random hash that is unique to each request. Affected products include: Laravel Framework.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 6.1 MEDIUM
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

DescriptionNVD

Laravel is a web application framework. Laravel prior to versions 8.75.0, 7.30.6, and 6.20.42 contain a possible cross-site scripting (XSS) vulnerability in the Blade templating engine. A broken HTML element may be clicked and the user taken to another location in their browser due to XSS. This is due to the user being able to guess the parent placeholder SHA-1 hash by trying common names of sections. If the parent template contains an exploitable HTML structure an XSS vulnerability can be exposed. This vulnerability has been patched in versions 8.75.0, 7.30.6, and 6.20.42 by determining the parent placeholder at runtime and using a random hash that is unique to each request.

Threat Intelligence Overview

EPSS Score
0.8%
Top 48% exploitable
Exploit
POC
Public exploit code exists
Data Quality
3 sources
Confidence: Low

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 Yes
EPSS 0.8%
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
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

51
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +30
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.

Affected Products (CPE)NVD

cpe:2.3:a:laravel:framework:*:*:*:*:*:*:*:*
cpe:2.3:a:laravel:framework:*:*:*:*:*:*:*:*
cpe:2.3:a:laravel:framework:*:*:*:*:*:*:*:*
CVE-2017-16894 HIGH POC
7.5 Nov 20

In Laravel framework through 5.5.21, remote attackers can obtain sensitive information (such as externally usable passwo

CVE-2025-54068 CRITICAL POC
9.8 Jul 17

Laravel Livewire v3 through v3.6.3 contains a critical remote code execution vulnerability (CVE-2025-54068, CVSS 9.8) th

CVE-2025-53833 CRITICAL POC
10.0 Jul 14

LaRecipe versions prior to 2.8.1 contain a Server-Side Template Injection (SSTI) vulnerability that can lead to Remote C

CVE-2026-28289 CRITICAL POC
10.0 Mar 03

File upload bypass in FreeScout 1.8.206 — patch bypass for CVE-2026-27636. PoC and patch available. CVSS 10.0.

CVE-2026-27636 HIGH POC
8.8 Feb 25

Remote code execution in FreeScout prior to version 1.8.206 allows authenticated users to upload `.htaccess` files that

CVE-2018-15133 HIGH POC
8.1 Aug 09

In Laravel Framework through 5.5.40 and 5.6.x through 5.6.29, remote code execution might occur as a result of an unseri

CVE-2025-70841 CRITICAL POC
10.0 Feb 03

Dokans SaaS e-commerce platform v3.9.2 has a CVSS 10.0 authentication bypass allowing unauthenticated attackers to obtai

CVE-2026-27637 CRITICAL POC
9.8 Feb 25

Predictable password reset tokens in FreeScout help desk before 1.8.206. Weak random number generation allows attackers

CVE-2026-21448 CRITICAL POC
9.8 Jan 02

Bagisto eCommerce platform before 2.3.10 is vulnerable to server-side template injection (SSTI) through customer address

CVE-2026-21446 CRITICAL POC
9.8 Jan 02

Bagisto eCommerce platform (2.3 branch before 2.3.10) leaves installation API routes active after setup, allowing unauth

CVE-2022-2870 CRITICAL POC
9.8 Aug 17

A vulnerability was found in laravel 5.1 and classified as problematic. Rated critical severity (CVSS 9.8), this vulnera

CVE-2026-114509 CRITICAL POC
9.2 Oct 21

Laravel TokenGuard authentication bypass is a genuine high-priority issue, not an inflated CVSS score: unauthenticated a

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