« Back to list

CVE-2026-73636

Status: AnalyzedHigh (8.1)—

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.

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).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

MITM attack (AV:N, AC:H) para capturar y reproducir credenciales digest. El atacante obtiene acceso autenticado (T1078) y puede manipular cuentas (T1098) tras el bypass de autenticación.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

User TrainingUser Account ManagementPrivileged Account ManagementNetwork SegmentationMulti-factor AuthenticationDisable or Remove Feature or Program

Affected technologies (1)

Apache — Http Server

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-73636",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-73636",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-01T19:43:35.472082Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.1,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.2
      }
    ]
  },
  "affected": [
    {
      "source": "security@apache.org",
      "affectedData": [
        {
          "vendor": "Apache Software Foundation",
          "product": "Apache HTTP Server",
          "versions": [
            {
              "status": "affected",
              "version": "2.4.0",
              "versionType": "semver",
              "lessThanOrEqual": "2.4.68"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-10-01T17:17:30.873",
  "references": [
    {
      "url": "https://httpd.apache.org/security/vulnerabilities_24.html",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "security@apache.org"
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2026/10/01/27",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security@apache.org",
      "description": [
        {
          "lang": "en",
          "value": "CWE-294"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.\n\nUsers are recommended to upgrade to version 2.4.69, which fixes this issue."
    }
  ],
  "lastModified": "2026-10-05T17:45:24.813",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "2571DF83-8980-4BEF-9EBE-AB2D9E6C03C7",
              "versionEndExcluding": "2.4.69",
              "versionStartIncluding": "2.4.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security@apache.org"
}