MediumCVE-2026-118505

    Team-alembic Ash Authentication: Improper Restriction of Excessive Authentication Attempts (CVE-2026-118505)

    Published Last modified Sources: CVE.org, OSV

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    What is affected, what to do

    Improper Restriction of Excessive Authentication Attempts vulnerability in team-alembic ash_authentication allows an unauthenticated attacker to guess passwords and one-time passwords without limit. The password, magic link and OTP strategies enforce brute_force_strategy by adding a preparation only to the actions they generate.

    Update Team-alembic Ash Authentication to version 5.0.0-rc.16.

    Affected
    • Team-alembic Ash Authentication lt 5.0.0-rc.4..5.0.0-rc.16
    Fixed in
    • Team-alembic Ash Authentication 5.0.0-rc.16

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

    Metrics

    6.3

    Priority

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

    Source: Vendor (CNA), CVSS v4

    6.3

    CVSS v4

    Severity Medium on the scale from 0 to 10.

    Source: CVE.org, OSV

    —

    EPSS score

    No value is available for this vulnerability.

    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
    61.50 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
    6.3 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
    6.3
    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 3 November 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-307

    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 Restriction of Excessive Authentication Attempts vulnerability in team-alembic ash_authentication allows an unauthenticated attacker to guess passwords and one-time passwords without limit. The password, magic link and OTP strategies enforce brute_force_strategy by adding a preparation only to the actions they generate. When the resource defines one of those actions itself, the strategy uses it as written and nothing checked that it carried the preparation, so the setting compiled and applied no limit. The generators produce exactly this: mix ash_authentication.install writes sign_in_with_password, request_password_reset_token and request_magic_link, mix ash_authentication.upgrade then adds brute_force_strategy to those strategies, and mix ash_authentication.add_strategy.otp writes its OTP actions without the preparation. Separately, with registration_enabled? true the OTP sign-in is a create action, which preparations do not run on, so brute_force_strategy {:preparation, module} never applied to it. This issue affects ash_authentication: from 5.0.0-rc.4 before 5.0.0-rc.16.

    Source: cvelistv5, NVD (NIST), CVE.org (MITRE), OSV (Open Source Vulnerabilities)

    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
    team-alembicash_authentication
    • 5.0.0-rc.4 – < 5.0.0-rc.16
    • 5.0.0-rc.16
    hexash_authentication
    • 5.0.0-rc.13
    • 5.0.0-rc.4
    • 5.0.0-rc.14
    • 5.0.0-rc.15
    • 5.0.0-rc.8
    • 5.0.0-rc.12
    • 5.0.0-rc.5
    • 5.0.0-rc.9
    • 5.0.0-rc.10
    • 5.0.0-rc.7
    • 5.0.0-rc.11
    • 5.0.0-rc.6
    • —
    • 5.0.0-rc.16
    • —
    • —
    • —
    • —
    • —
    • —
    • —
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    Vendors and products

    Weakness classes (CWE)

    • CWE-307Improper Restriction of Excessive Authentication Attempts

      Base

      The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.

      Entry at MITRE CWE-307

    References & sources

    • github.com`brute_force_strategy` in AshAuthentication does not protect sign-in and request actions defined on the resource, allowing unlimited password and one-time password guessingadvisory, Vendor advisory, related
    • cna.erlef.orgEEF CNA record for CVE-2026-118505web, related
    • github.comIntroducing commit 800caa0 in team-alembic/ash_authenticationweb, related
    • github.comFix commit 7117b5d in team-alembic/ash_authenticationfix, Patch
    • hex.pmpackages/ash_authenticationpackage
    • OSV (Open Source Vulnerabilities)OSV record EEF-CVE-2026-118505related

    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: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-118505","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-11-03T17:47:46.366690Z"}

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

    2. ReceivedEEF

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

      Weakness type: CWE-307

      Description added or changed

      Show 9 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      Improper Restriction of Excessive Authentication Attempts vulnerability in team-alembic ash_authentication allows an unauthenticated attacker to guess passwords and one-time passwords without limit. The password, magic link and OTP strategies enforce brute_force_strategy by adding a preparation only to the actions they generate. When the resource defines one of those actions itself, the strategy uses it as written and nothing checked that it carried the preparation, so the setting compiled and applied no limit. The generators produce exactly this: mix ash_authentication.install writes sign_in_with_password, request_password_reset_token and request_magic_link, mix ash_authentication.upgrade then adds brute_force_strategy to those strategies, and mix ash_authentication.add_strategy.otp writes its OTP actions without the preparation. Separately, with registration_enabled? true the OTP sign-in is a create action, which preparations do not run on, so brute_force_strategy {:preparation, module} never applied to it. This issue affects ash_authentication: from 5.0.0-rc.4 before 5.0.0-rc.16.
      CVSSadded
      —
      AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/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-307
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/118xxx/CVE-2026-118505.json">CVE-2026-118505</a>
      Referenceadded
      —
      https://cna.erlef.org/cves/CVE-2026-118505.html
      Referenceadded
      —
      https://github.com/team-alembic/ash_authentication/commit/7117b5da5b73ee4cdb372e4adfbaff409b527125
      Referenceadded
      —
      https://github.com/team-alembic/ash_authentication/commit/800caa0d4a5bee1f28ad427f4c12fab72003a577
      Referenceadded
      —
      https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-55gf-3263-4r39
      Referenceadded
      —
      https://osv.dev/vulnerability/EEF-CVE-2026-118505

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

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