FKIE_CVE-2026-71303

Vulnerability from fkie_nvd - Published: 2026-08-18 20:17 - Updated: 2026-08-18 20:17
Severity
7.7 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Summary
Lemur manages TLS certificate creation. Prior to 1.9.3, _validate_acme_url enforced ACME_DIRECTORY_HOST_ALLOWLIST when an authority was created, but PUT /api/1/authorities/ passed options to lemur/authorities/service.py without applying the same check. A user holding an authority role could replace the stored acme_url with an internal service or instance-metadata URL such as 169.254.169.254. The next issuance operation loaded that value and passed it to ClientV2.get_directory, causing an outbound request from the Lemur backend. This bypassed the creation-time mitigation for CVE-2026-55166 and could expose internal services or cloud metadata. The fix revalidates acme_url whenever authority options are updated. This issue is fixed in version 1.9.3.
References
security-advisories@github.comhttps://github.com/Netflix/lemur/commit/edca0390f930344d65ff4ca37a669c2320e3dfad
security-advisories@github.comhttps://github.com/Netflix/lemur/releases/tag/v1.9.3
security-advisories@github.comhttps://github.com/Netflix/lemur/security/advisories/GHSA-v5rc-cpwc-cfpr
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/Netflix/lemur/security/advisories/GHSA-v5rc-cpwc-cfpr
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "lemur",
          "vendor": "Netflix",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.9.3"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Lemur manages TLS certificate creation. Prior to 1.9.3, _validate_acme_url enforced ACME_DIRECTORY_HOST_ALLOWLIST when an authority was created, but PUT /api/1/authorities/ passed options to lemur/authorities/service.py without applying the same check. A user holding an authority role could replace the stored acme_url with an internal service or instance-metadata URL such as 169.254.169.254. The next issuance operation loaded that value and passed it to ClientV2.get_directory, causing an outbound request from the Lemur backend. This bypassed the creation-time mitigation for CVE-2026-55166 and could expose internal services or cloud metadata. The fix revalidates acme_url whenever authority options are updated. This issue is fixed in version 1.9.3."
    }
  ],
  "id": "CVE-2026-71303",
  "lastModified": "2026-08-18T20:17:23.403",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.7,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.1,
        "impactScore": 4.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-71303",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-18T19:45:59.586663Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-18T20:17:23.403",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Netflix/lemur/commit/edca0390f930344d65ff4ca37a669c2320e3dfad"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Netflix/lemur/releases/tag/v1.9.3"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Netflix/lemur/security/advisories/GHSA-v5rc-cpwc-cfpr"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/Netflix/lemur/security/advisories/GHSA-v5rc-cpwc-cfpr"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}



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