FKIE_CVE-2026-56743

Vulnerability from fkie_nvd - Published: 2026-07-15 20:17 - Updated: 2026-07-15 20:54
Severity
5.4 (Medium) - CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Summary
Cilium is a networking, observability, and security solution. From 1.19.0 to 1.19.4, standard Kubernetes NetworkPolicy specifications using CIDR-based ipBlock rules without pod or namespace selectors erroneously generate a wildcard namespace allow rule when Cilium is configured with a custom clusterName rather than the default any value. The parser incorrectly instantiates a pod selector on selectorless peer definitions, allowing traffic from other workloads in the same namespace as the subject of the policy. This issue is fixed in version 1.19.5.
References
security-advisories@github.comhttps://github.com/cilium/cilium/commit/1c84ae3b58a7cd54f7ee355e6c524c82f620eae8
security-advisories@github.comhttps://github.com/cilium/cilium/commit/bacea640404c0805c23515353dc1681c5bf35171
security-advisories@github.comhttps://github.com/cilium/cilium/pull/46305
security-advisories@github.comhttps://github.com/cilium/cilium/pull/46456
security-advisories@github.comhttps://github.com/cilium/cilium/releases/tag/v1.19.5
security-advisories@github.comhttps://github.com/cilium/cilium/security/advisories/GHSA-fm8w-2m5w-9j7r
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "cilium",
          "vendor": "cilium",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.19.0, \u003c 1.19.5"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Cilium is a networking, observability, and security solution. From 1.19.0 to 1.19.4, standard Kubernetes NetworkPolicy specifications using CIDR-based ipBlock rules without pod or namespace selectors erroneously generate a wildcard namespace allow rule when Cilium is configured with a custom clusterName rather than the default any value. The parser incorrectly instantiates a pod selector on selectorless peer definitions, allowing traffic from other workloads in the same namespace as the subject of the policy. This issue is fixed in version 1.19.5."
    }
  ],
  "id": "CVE-2026-56743",
  "lastModified": "2026-07-15T20:54:43.733",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.4,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.3,
        "impactScore": 2.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-15T20:17:51.987",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/cilium/cilium/commit/1c84ae3b58a7cd54f7ee355e6c524c82f620eae8"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/cilium/cilium/commit/bacea640404c0805c23515353dc1681c5bf35171"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/cilium/cilium/pull/46305"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/cilium/cilium/pull/46456"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/cilium/cilium/releases/tag/v1.19.5"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/cilium/cilium/security/advisories/GHSA-fm8w-2m5w-9j7r"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-863"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.