CVE-2026-78391
Stored Cross-Site Scripting via Untrusted Cryptocurrency Address Rendering in RansomLook
Description
RansomLook contains a stored cross-site scripting (XSS) vulnerability in the cryptocurrency wallet detail view. Cryptocurrency addresses and blockchain names originating from external sources, including the public crowd-sourced ransomwhe.re feed, were stored without sufficient validation and later embedded directly into an inline JavaScript onclick handler. Although Jinja HTML autoescaping was applied, it does not provide adequate protection when untrusted data is inserted into a JavaScript string inside an HTML attribute. HTML entities such as ' are decoded by the browser's HTML parser before the resulting attribute is interpreted as JavaScript. Consequently, a specially crafted cryptocurrency address containing quote characters and JavaScript syntax could escape the intended string literal and execute arbitrary JavaScript when a user clicked the affected wallet's CSV export button. Because cryptocurrency information imported from an untrusted upstream could reach the vulnerable rendering path, exploitation may not require an authenticated RansomLook account if an attacker can introduce a malicious wallet record into a consumed external data source. Successful exploitation could allow attacker-controlled JavaScript to execute in the security context of the RansomLook web application, potentially exposing information accessible to the victim or performing actions with the victim's privileges. The patch mitigates the issue by validating cryptocurrency addresses and blockchain identifiers before storage, restricting them to a safe character set, and replacing the inline JavaScript handler with data-* attributes and an external event listener so wallet values are treated strictly as data rather than executable JavaScript.
INFO
Published Date :
Aug. 24, 2026, 3:16 p.m.
Last Modified :
Oct. 14, 2026, 1:10 p.m.
Remotely Exploit :
Yes !
Source :
5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | ||||
| CVSS 4.0 | HIGH | 5a6e4751-2f3f-4070-9419-94fb35b644e8 |
Solution
- Validate cryptocurrency addresses and blockchain identifiers.
- Sanitize user-supplied input.
- Avoid embedding untrusted data directly into JavaScript.
- Use external event listeners for data handling.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-78391.
| URL | Resource |
|---|---|
| https://github.com/RansomLook/RansomLook/commit/7efb59253f23552538f9a11c9bf21e7bcfcc1319 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-78391 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-78391
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-78391 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-78391 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Oct. 14, 2026
Action Type Old Value New Value Added Translation Title: ransomlook, Description: RansomLook contiene una vulnerabilidad de cross-site scripting (XSS) almacenado en la vista de detalles de la billetera de criptomonedas. Las direcciones de criptomonedas y los nombres de blockchain originados de fuentes externas, incluyendo el feed público de crowd-sourced ransomwhe.re, se almacenaron sin validación suficiente y luego se incrustaron directamente en un gestor onclick de JavaScript en línea. Aunque se aplicó el autoescape HTML de Jinja, no proporciona protección adecuada cuando se insertan datos no confiables en una cadena de JavaScript dentro de un atributo HTML. Las entidades HTML como ' son decodificadas por el analizador HTML del navegador antes de que el atributo resultante sea interpretado como JavaScript. En consecuencia, una dirección de criptomoneda especialmente diseñada que contenga caracteres de comillas y sintaxis de JavaScript podría escapar del literal de cadena previsto y ejecutar JavaScript arbitrario cuando un usuario hiciera clic en el botón de exportación CSV de la billetera afectada. Debido a que la información de criptomonedas importada de una fuente ascendente no confiable podría alcanzar la ruta de renderizado vulnerable, la explotación podría no requerir una cuenta autenticada de RansomLook si un atacante puede introducir un registro de billetera malicioso en una fuente de datos externa consumida. La explotación exitosa podría permitir que JavaScript controlado por el atacante se ejecute en el contexto de seguridad de la aplicación web RansomLook, exponiendo potencialmente información accesible para la víctima o realizando acciones con los privilegios de la víctima. El parche mitiga el problema validando las direcciones de criptomonedas y los identificadores de blockchain antes del almacenamiento, restringiéndolos a un conjunto de caracteres seguro y reemplazando el gestor de JavaScript en línea con atributos data-* y un oyente de eventos externo para que los valores de la billetera se traten estrictamente como datos en lugar de JavaScript ejecutable. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 24, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-78391', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-24T15:08:03.216450Z'} -
New CVE Received by 5a6e4751-2f3f-4070-9419-94fb35b644e8
Aug. 24, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/RansomLook/RansomLook', 'vendor': 'ransomlook', 'product': 'ransomlook', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.0.0'}], 'defaultStatus': 'unaffected'}] Added Description RansomLook contains a stored cross-site scripting (XSS) vulnerability in the cryptocurrency wallet detail view. Cryptocurrency addresses and blockchain names originating from external sources, including the public crowd-sourced ransomwhe.re feed, were stored without sufficient validation and later embedded directly into an inline JavaScript onclick handler. Although Jinja HTML autoescaping was applied, it does not provide adequate protection when untrusted data is inserted into a JavaScript string inside an HTML attribute. HTML entities such as ' are decoded by the browser's HTML parser before the resulting attribute is interpreted as JavaScript. Consequently, a specially crafted cryptocurrency address containing quote characters and JavaScript syntax could escape the intended string literal and execute arbitrary JavaScript when a user clicked the affected wallet's CSV export button. Because cryptocurrency information imported from an untrusted upstream could reach the vulnerable rendering path, exploitation may not require an authenticated RansomLook account if an attacker can introduce a malicious wallet record into a consumed external data source. Successful exploitation could allow attacker-controlled JavaScript to execute in the security context of the RansomLook web application, potentially exposing information accessible to the victim or performing actions with the victim's privileges. The patch mitigates the issue by validating cryptocurrency addresses and blockchain identifiers before storage, restricting them to a safe character set, and replacing the inline JavaScript handler with data-* attributes and an external event listener so wallet values are treated strictly as data rather than executable JavaScript. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-79 Added Reference https://github.com/RansomLook/RansomLook/commit/7efb59253f23552538f9a11c9bf21e7bcfcc1319