CVE-2026-71502
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.
- Exploit odds
- 0.7% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.7% in the next 30 days (EPSS).
- Severity: 5.1 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.7% · EPSS, next 30 days
- Weakness
- CWE-79 · Cross-site scripting
- Record status
- Deferred
Attack profile CVSS 4.0 · 5.1
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- None
- Privileges needed
- None
- User interaction
- Active
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:4.0/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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-71502.md and follow it. Check whether this project is affected by CVE-2026-71502. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/MISP/cti-transmute/commit/4f43c9181a00262bec2a6dfbc9ff9c50d534e918
- https://github.com/MISP/cti-transmute/commit/522fa8ff8223b12a6128ea3fc2344a77b7b9108d
- https://github.com/MISP/cti-transmute/commit/ad8bf2b8031491cefb552314ef7ff6f4148ca95a
- https://github.com/MISP/cti-transmute/commit/ecfdaef63860a071c6f07afd30156ca77a77ad2b
References
- https://github.com/MISP/cti-transmute/commit/4f43c9181a00262bec2a6dfbc9ff9c50d534e918
- https://github.com/MISP/cti-transmute/commit/522fa8ff8223b12a6128ea3fc2344a77b7b9108d
- https://github.com/MISP/cti-transmute/commit/ad8bf2b8031491cefb552314ef7ff6f4148ca95a
- https://github.com/MISP/cti-transmute/commit/ecfdaef63860a071c6f07afd30156ca77a77ad2b