5.1
MEDIUM CVSS 4.0
CVE-2026-71502
Unauthenticated Stored Vue Template Injection Leads to Cross-Site Scripting in CTI-Transmute
Description

CTI-Transmute contains a stored cross-site scripting vulnerability caused by insufficient neutralization of Vue template expression delimiters in server-rendered user-controlled data. An unauthenticated attacker can create a public conversion whose name or description contains a malicious Vue expression using the application's configured [[ ... ]] delimiters. User profile names may provide an additional injection vector. Although Jinja HTML escaping is applied, the resulting value is subsequently included in a DOM region compiled by Vue. Vue interprets the attacker-controlled value as a template expression rather than ordinary text. By accessing the JavaScript Function constructor from within the expression, an attacker can execute arbitrary JavaScript in the security context of the CTI-Transmute origin. The application's nonce-based Content Security Policy does not prevent exploitation because the Vue runtime compiler requires the unsafe-eval policy exception. The malicious payload is stored by the application and executed whenever another user opens an affected page, such as the public conversion detail page. The victim may be a normal user or an administrator. Successful exploitation could allow the attacker to: * Access data available to the victim through the application. * Extract API keys, tokens, or other sensitive information exposed to the page. * Perform authenticated actions using the victim's session. * Modify conversions or other application data. * Escalate the impact by targeting an administrator. A demonstrated payload can use [].constructor.constructor(...) to obtain the JavaScript Function constructor and execute arbitrary code. The regression tests also show that a short first-stage payload could retrieve an uncapped conversion description and evaluate a larger second-stage payload. The patch addresses the vulnerability by registering a global Jinja finalize hook that inserts a zero-width Unicode word joiner inside every Vue delimiter found in server-rendered values. This prevents Vue from recognizing the values as template expressions while preserving their visible representation.

INFO

Published Date :

Aug. 8, 2026, 10:16 p.m.

Last Modified :

Aug. 8, 2026, 10:16 p.m.

Remotely Exploit :

Yes !

Source :

5a6e4751-2f3f-4070-9419-94fb35b644e8
Affected Products

The following products are affected by CVE-2026-71502 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 4.0 MEDIUM 5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS 4.0 MEDIUM 5a6e4751-2f3f-4070-9419-94fb35b644e8
Solution
Patch the application to prevent Vue from interpreting user-controlled data as template expressions.
  • Apply the vendor patch to register a Jinja finalize hook.
  • Insert a zero-width word joiner within Vue delimiters.
  • Prevent Vue from recognizing data as template expressions.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-71502 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-2026-71502 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-2026-71502 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-71502 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.

  • New CVE Received by 5a6e4751-2f3f-4070-9419-94fb35b644e8

    Aug. 08, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/MISP/cti-transmute', 'vendor': 'misp', 'product': 'cti-transmute', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '1.4.0'}], 'defaultStatus': 'unaffected'}]
    Added Description CTI-Transmute contains a stored cross-site scripting vulnerability caused by insufficient neutralization of Vue template expression delimiters in server-rendered user-controlled data. An unauthenticated attacker can create a public conversion whose name or description contains a malicious Vue expression using the application's configured [[ ... ]] delimiters. User profile names may provide an additional injection vector. Although Jinja HTML escaping is applied, the resulting value is subsequently included in a DOM region compiled by Vue. Vue interprets the attacker-controlled value as a template expression rather than ordinary text. By accessing the JavaScript Function constructor from within the expression, an attacker can execute arbitrary JavaScript in the security context of the CTI-Transmute origin. The application's nonce-based Content Security Policy does not prevent exploitation because the Vue runtime compiler requires the unsafe-eval policy exception. The malicious payload is stored by the application and executed whenever another user opens an affected page, such as the public conversion detail page. The victim may be a normal user or an administrator. Successful exploitation could allow the attacker to: * Access data available to the victim through the application. * Extract API keys, tokens, or other sensitive information exposed to the page. * Perform authenticated actions using the victim's session. * Modify conversions or other application data. * Escalate the impact by targeting an administrator. A demonstrated payload can use [].constructor.constructor(...) to obtain the JavaScript Function constructor and execute arbitrary code. The regression tests also show that a short first-stage payload could retrieve an uncapped conversion description and evaluate a larger second-stage payload. The patch addresses the vulnerability by registering a global Jinja finalize hook that inserts a zero-width Unicode word joiner inside every Vue delimiter found in server-rendered values. This prevents Vue from recognizing the values as template expressions while preserving their visible representation.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/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 CWE CWE-1336
    Added Reference https://github.com/MISP/cti-transmute/commit/4f43c9181a00262bec2a6dfbc9ff9c50d534e918
    Added Reference https://github.com/MISP/cti-transmute/commit/522fa8ff8223b12a6128ea3fc2344a77b7b9108d
    Added Reference https://github.com/MISP/cti-transmute/commit/ad8bf2b8031491cefb552314ef7ff6f4148ca95a
    Added Reference https://github.com/MISP/cti-transmute/commit/ecfdaef63860a071c6f07afd30156ca77a77ad2b
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 08, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-71502', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-07T13:57:26.854958Z'}
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.