MediumCVE-2026-71502

    Unauthenticated Stored Vue Template Injection Leads to Cross-Site Scripting in CTI-Transmute (CVE-2026-71502)

    Published Last modified Sources: EUVD, CVE.org

    What is affected, what to do

    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.

    The available sources name no fixed version. Check the vendor guidance in the references below.

    Affected
    • MISP Cti-transmute lte *..1.4.0

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    5.1

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v4

    5.1

    CVSS v4

    Severity Medium on the scale from 0 to 10.

    Source: EUVD, CVE.org

    0.7 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 54.5

    Show all metrics
    Severity
    Medium
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    71.66 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    5.1 Methodology
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    5.1
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

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    0.7 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    54.5
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 7 August 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-79, CWE-1336

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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.

    Source: ENISA EUVD, cvelistv5, NVD (NIST), CVE.org (MITRE)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    mispcti-transmute
    • ≤ 1.4.0
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

      Base

      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.

      Entry at MITRE CWE-79

    • CWE-1336Improper Neutralization of Special Elements Used in a Template Engine

      Base

      The product uses a template engine to insert or process externally-influenced input, but it does not neutralize or incorrectly neutralizes special elements or syntax that can be interpreted as template expressions or other code directives when processed by the engine.

      Entry at MITRE CWE-1336

    References & sources

    • Original source
    • github.comMISP/cti-transmute/commit/ecfdaef63860a071c6f07afd30156ca77a77a…Patch
    • github.comMISP/cti-transmute/commit/522fa8ff8223b12a6128ea3fc2344a77b7b91…Patch
    • github.comMISP/cti-transmute/commit/ad8bf2b8031491cefb552314ef7ff6f4148ca…Patch
    • github.comMISP/cti-transmute/commit/4f43c9181a00262bec2a6dfbc9ff9c50d534e…Patch

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. ReceivedCIRCL

      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

      Weakness type: CWE-79, CWE-1336

      Description added or changed

      Show 9 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      cti-transmute
      Descriptionadded
      —
      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.
      CVSSadded
      —
      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
      Weakness type (CWE)added
      —
      CWE-79
      Weakness type (CWE)added
      —
      CWE-1336
      Referenceadded
      —
      https://github.com/MISP/cti-transmute/commit/4f43c9181a00262bec2a6dfbc9ff9c50d534e918
      Referenceadded
      —
      https://github.com/MISP/cti-transmute/commit/522fa8ff8223b12a6128ea3fc2344a77b7b9108d
      Referenceadded
      —
      https://github.com/MISP/cti-transmute/commit/ad8bf2b8031491cefb552314ef7ff6f4148ca95a
      Referenceadded
      —
      https://github.com/MISP/cti-transmute/commit/ecfdaef63860a071c6f07afd30156ca77a77ad2b

      Source identifier: 5a6e4751-2f3f-4070-9419-94fb35b644e8

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"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"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    2 NVD translations into other languages are hidden.

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