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CVE-2026-23901

Status: AnalyzedLow (1)—

Observable Timing Discrepancy vulnerability in Apache Shiro.

This issue affects Apache Shiro: from 1.*, 2.* before 2.0.7.

Users are recommended to upgrade to version 2.0.7 or later, which fixes the issue.

Prior to Shiro 2.0.7, code paths for non-existent vs. existing users are different enough, that a brute-force attack may be able to tell, by timing the requests only, determine if the request failed because of a non-existent user vs. wrong password.

The most likely attack vector is a local attack only. Shiro security model  https://shiro.apache.org/security-model.html#username_enumeration  discusses this as well.

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Typically, brute force attack can be mitigated at the infrastructure level.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Apache — Shiro

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2026-23901",
  "cveTags": [],
  "metrics": {
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          "timestamp": "2026-02-10T15:31:09.515973Z"
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          "confidentialityImpact": "LOW"
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          "exploitMaturity": "NOT_DEFINED",
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          "integrityRequirement": "NOT_DEFINED",
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          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
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          "modifiedAttackRequirements": "NOT_DEFINED",
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          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
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          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
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  "published": "2026-02-10T10:15:59.240",
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  "weaknesses": [
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      "source": "security@apache.org",
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          "value": "CWE-208"
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      "lang": "en",
      "value": "Observable Timing Discrepancy vulnerability in Apache Shiro.\n\nThis issue affects Apache Shiro: from 1.*, 2.* before 2.0.7.\n\nUsers are recommended to upgrade to version 2.0.7 or later, which fixes the issue.\n\nPrior to Shiro 2.0.7, code paths for non-existent vs. existing users are different enough,\nthat a brute-force attack may be able to tell, by timing the requests only, determine if\nthe request failed because of a non-existent user vs. wrong password.\n\nThe most likely attack vector is a local attack only.\nShiro security model  https://shiro.apache.org/security-model.html#username_enumeration  discusses this as well.\n\nTypically, brute force attack can be mitigated at the infrastructure level."
    },
    {
      "lang": "es",
      "value": "Vulnerabilidad de discrepancia de tiempo observable en Apache Shiro.\n\nEste problema afecta a Apache Shiro: desde 1.*, 2.* antes de 2.0.7.\n\nSe recomienda a los usuarios actualizar a la versión 2.0.7 o posterior, que soluciona el problema.\n\nAntes de Shiro 2.0.7, las rutas de código para usuarios inexistentes frente a usuarios existentes son lo suficientemente diferentes como para que un ataque de fuerza bruta pueda discernir, solo cronometrando las solicitudes, si la solicitud falló debido a un usuario inexistente frente a una contraseña incorrecta.\n\nEl vector de ataque más probable es solo un ataque local.\nEl modelo de seguridad de Shiro https://shiro.apache.org/security-model.html#username_enumeration también aborda esto.\n\nTípicamente, el ataque de fuerza bruta puede mitigarse a nivel de infraestructura."
    }
  ],
  "lastModified": "2026-06-17T10:22:16.960",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
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