MediumCVE-2026-115274

    Elixir: Improper Validation of Specified Quantity in Input (CVE-2026-115274)

    Published Last modified Sources: CVE.org, OSV

    What is affected, what to do

    Improper Validation of Specified Quantity in Input vulnerability in the Elixir standard library's JSON module allows an unauthenticated attacker who supplies a JSON document to cause a denial of service through CPU and memory exhaustion. JSON.decode/1 and JSON.decode!/1 convert each integer literal with erlang:binary_to_integer/1 and do not bound its length.

    Update Elixir to version 1.18.6, Elixir to version 1.19.7, Elixir to version 1.20.5.

    Affected
    • Elixir lt 1.18.0-rc.0..1.18.6
    • Elixir lt 1.19.0-rc.0..1.19.7
    • Elixir lt 1.20.0-rc.0..1.20.5
    Fixed in
    • Elixir 1.18.6
    • Elixir 1.19.7
    • Elixir 1.20.5

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

    Metrics

    6.9

    Priority

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

    Source: Vendor (CNA), CVSS v4

    6.9

    CVSS v4

    Severity Medium on the scale from 0 to 10.

    Source: CVE.org, OSV

    0.5 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 42.7

    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
    79.10 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
    6.9 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
    6.9
    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“.

    Read in glossary
    0.5 %
    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
    42.7
    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: proof of concept · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 30 October 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-1284

    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

    Improper Validation of Specified Quantity in Input vulnerability in the Elixir standard library's JSON module allows an unauthenticated attacker who supplies a JSON document to cause a denial of service through CPU and memory exhaustion. JSON.decode/1 and JSON.decode!/1 convert each integer literal with erlang:binary_to_integer/1 and do not bound its length. A literal of one million digits decodes successfully but costs 100 to 300 times as much CPU as a string of the same length, so one request body of a few megabytes holds a scheduler for about a second. A literal of more than about 1.29 million digits raises SystemLimitError. Applications generated by phx.new decode request bodies with JSON in Plug.Parsers, before routing and authentication. This issue affects elixir: from 1.18.0-rc.0 before 1.18.6, from 1.19.0-rc.0 before 1.19.7, and from 1.20.0-rc.0 before 1.20.5.

    Source: NVD (NIST), cvelistv5, OSV (Open Source Vulnerabilities), 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
    elixir-langelixir
    • 1.19.0-rc.0 – < 1.19.7
    • 1.18.0-rc.0 – < 1.18.6
    • 1.20.0-rc.0 – < 1.20.5
    • 1.19.7
    • 1.18.6
    • 1.20.5

    Vendors and products

    Weakness classes (CWE)

    • CWE-1284Improper Validation of Specified Quantity in Input

      Base

      The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.

      Entry at MITRE CWE-1284

    References & sources

    • github.comUnbounded integer parsing in JSON.decode/1 enables CPU and memory exhaustion denial of service in Elixiradvisory, Vendor advisory, related
    • cna.erlef.orgEEF CNA record for CVE-2026-115274web, related
    • github.comIntroducing commit 793c114 in elixir-lang/elixirweb, related
    • github.comFix commit c81f122 in elixir-lang/elixirfix, Patch
    • github.comFix commit 7154e87 in elixir-lang/elixirfix, Patch
    • github.comFix commit cd158ef in elixir-lang/elixirfix, Patch
    • github.comFix commit ee5cc23 in elixir-lang/elixirfix, Patch
    • OSV (Open Source Vulnerabilities)OSV record EEF-CVE-2026-115274related

    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. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: proof of concept, automatable: yes

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://github.com/elixir-lang/elixir/security/advisories/GHSA-rp5q-xqhq-926h
      SSVC assessmentadded
      —
      {"id":"CVE-2026-115274","role":"CISA Coordinator","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-30T16:51:17.679403Z"}

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

    2. ReceivedEEF

      CVSS V4.0: AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

      Weakness type: CWE-1284

      Description added or changed

      Show 12 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      Improper Validation of Specified Quantity in Input vulnerability in the Elixir standard library's JSON module allows an unauthenticated attacker who supplies a JSON document to cause a denial of service through CPU and memory exhaustion. JSON.decode/1 and JSON.decode!/1 convert each integer literal with erlang:binary_to_integer/1 and do not bound its length. A literal of one million digits decodes successfully but costs 100 to 300 times as much CPU as a string of the same length, so one request body of a few megabytes holds a scheduler for about a second. A literal of more than about 1.29 million digits raises SystemLimitError. Applications generated by phx.new decode request bodies with JSON in Plug.Parsers, before routing and authentication. This issue affects elixir: from 1.18.0-rc.0 before 1.18.6, from 1.19.0-rc.0 before 1.19.7, and from 1.20.0-rc.0 before 1.20.5.
      CVSSadded
      —
      AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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
      Weakness type (CWE)added
      —
      CWE-1284
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/115xxx/CVE-2026-115274.json">CVE-2026-115274</a>
      Referenceadded
      —
      https://cna.erlef.org/cves/CVE-2026-115274.html
      Referenceadded
      —
      https://github.com/elixir-lang/elixir/commit/7154e8781da9fd016a973ea01776a011c8b5726a
      Referenceadded
      —
      https://github.com/elixir-lang/elixir/commit/793c1147210388587defb649f25f293ffbfa6b1b
      Referenceadded
      —
      https://github.com/elixir-lang/elixir/commit/c81f12265919c34a0d5134f1905a4eb4edaea1c2
      Referenceadded
      —
      https://github.com/elixir-lang/elixir/commit/cd158efacdc10b30232864251747dff9b8387dfe
      Referenceadded
      —
      https://github.com/elixir-lang/elixir/commit/ee5cc23f8928aa5a0f25bb7f28e42ecfc7b7d396
      Referenceadded
      —
      https://github.com/elixir-lang/elixir/security/advisories/GHSA-rp5q-xqhq-926h
      Referenceadded
      —
      https://osv.dev/vulnerability/EEF-CVE-2026-115274

      Source identifier: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

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