HighCVE-2026-116584

    Seroval `fromJSON`/`fromCrossJSON` denial of service via unvalidated array node length (CVE-2026-116584)

    Published Last modified Sources: OSV, Hersteller, CVE.org

    What is affected, what to do

    Update seroval to version 1.6.8.

    Affected
    • Lxsmnsyc Seroval gte 1.4.1, < 1.6.8..*

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

    Metrics

    7.5

    Priority

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

    Source: Vendor (CNA), CVSS v3

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: OSV, Hersteller, CVE.org

    0.4 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 30.3

    Show all metrics
    Severity
    High
    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
    74.85 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
    7.5 Methodology
    CVSS v3

    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
    7.5
    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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    0.4 %
    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
    30.3
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    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
    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-770

    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
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    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

    Summary

    fromJSON and fromCrossJSON did not check that an array node's element list is an array. A small crafted payload could set the length the decoder used. That length controlled how much memory was allocated and how many times the decoder looped, and it did not depend on the size of the payload.

    Impact

    A service that passes untrusted input to fromJSON or fromCrossJSON can be made unavailable by an unauthenticated request.

    • A small payload can allocate enough memory to end the process.
    • A small payload can block the thread for seconds, or without end.

    This affects any framework that decodes request bodies with these functions before its own validation runs.

    This issue is a bypass of the fix for GHSA-66fc-rw6m-c2q6 in 1.4.1.

    Patches

    Fixed in seroval@1.6.8. The deserializer now rejects any node whose element list is not an array, and throws SerovalMalformedNodeError.

    Workarounds

    None. Upgrade to 1.6.8.

    Source: OSV (Open Source Vulnerabilities), GitHub Security Advisories, cvelistv5, NVD (NIST)

    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
    lxsmnsycseroval
    • ≥ 1.4.1, < 1.6.8
    • —
    npmseroval
    • >= 1.4.1, <= 1.6.7
    • 1.4.1
    • 1.6.8
    • 1.6.8

    Vendors and products

    Weakness classes (CWE)

    • CWE-770Allocation of Resources Without Limits or Throttling

      Base

      The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

      Entry at MITRE CWE-770

    References & sources

    • github.comlxsmnsyc/seroval/commit/cdcee3e3bc384ee844360844f8ea98fd2b275d69x_refsource_MISC, web
    • github.comlxsmnsyc/seroval/releases/tag/seroval@1.6.8x_refsource_MISC, web
    • github.comlxsmnsyc/seroval/security/advisories/GHSA-wp97-x4hv-qvhpx_refsource_CONFIRM, web
    • NVD (NIST)vuln/detail/CVE-2026-116584advisory
    • github.comlxsmnsyc/serovalpackage

    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. ReceivedGitHub

      CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

      Weakness type: CWE-770

      Description added or changed

      Show 7 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. From 1.4.1 until 1.6.8, fromJSON and fromCrossJSON do not require an array node's element list to be an actual array. A small crafted payload can supply an attacker-controlled length that determines memory allocation and decoder iterations independently of payload size, allowing an unauthenticated request to exhaust the process or block its thread. This issue is a residual bypass of the remediation for CVE-2026-23957. This issue is fixed in version 1.6.8.
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
      Weakness type (CWE)added
      —
      CWE-770
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/116xxx/CVE-2026-116584.json">CVE-2026-116584</a>
      Referenceadded
      —
      https://github.com/lxsmnsyc/seroval/commit/cdcee3e3bc384ee844360844f8ea98fd2b275d69
      Referenceadded
      —
      https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.8
      Referenceadded
      —
      https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-wp97-x4hv-qvhp

      Source identifier: security-advisories@github.com

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