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CVE-2026-112112

Status: DeferredLow (2.3)—
Severity2.3Low · CVSS 4.0
Exploitation probability0.31 %higher than 22% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

An IPv6 FlowSpec validation bypass in the CZ.NIC BIRD Internet Routing Daemon allows an established BGP peer to inject FlowSpec rules matching destinations outside the address space authorized by the unicast-route validation procedure. With validation enabled on the receiving flow6 channel, BIRD fails to reject a destination prefix component with a nonzero offset, contrary to RFC 8956 section 5. It validates a reconstructed prefix with zero-filled skipped bits, although the original FlowSpec component can match a broader set of IPv6 addresses. Given a suitable unicast route from the peer, the rule can pass validation and, where export policy permits, be propagated to downstream peers. Downstream enforcement may cause unauthorized traffic filtering or redirection.

CVSS

Base score
2.3
Version
4.0
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/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

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.31 %
Percentile among all scored CVEs
22
Score date
10/22/2026

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.

Vector AV:N/PR:L/UI:N: explotable por red desde un peer BGP establecido; la regla FlowSpec pasa la validación y puede propagarse, causando filtrado o redirección de tráfico no autorizado.

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

Vulnerability ScanningThreat Intelligence ProgramPrivileged Account ManagementNetwork SegmentationFilter Network TrafficEncrypt Sensitive Information

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Cz.nic — BirdAI

CWEs

References

Show 4 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-112112",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-112112",
          "role": "CISA Coordinator",
          "options": [
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              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
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          ],
          "version": "2.0.3",
          "timestamp": "2026-10-19T18:39:04.870755Z"
        }
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    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "cve@mitre.org",
        "cvssData": {
          "Safety": "NOT_DEFINED",
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          "Recovery": "NOT_DEFINED",
          "baseScore": 2.3,
          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "LOW",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/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",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "LOW",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "LOW",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
        }
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    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "repo": "https://gitlab.nic.cz/labs/bird",
          "vendor": "nic",
          "modules": [
            "IPv6 FlowSpec validation"
          ],
          "product": "BIRD",
          "versions": [
            {
              "status": "affected",
              "version": "2.0.9",
              "versionType": "semver",
              "lessThanOrEqual": "2.20.0"
            },
            {
              "status": "affected",
              "version": "3.0.0",
              "versionType": "semver",
              "lessThanOrEqual": "3.4.0"
            }
          ],
          "programFiles": [
            "nest/rt-table.c"
          ],
          "defaultStatus": "unknown",
          "programRoutines": [
            {
              "name": "net_flow_has_dst_prefix"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-10-18T23:16:56.767",
  "references": [
    {
      "url": "https://gitlab.nic.cz/labs/bird/-/blob/v2.20.0/nest/rt-table.c#L2686",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://gitlab.nic.cz/labs/bird/-/blob/v3.4.0/nest/rt-table.c#L4518",
      "source": "cve@mitre.org"
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    {
      "url": "https://gitlab.nic.cz/labs/bird/-/commit/7cf75587b6f38b87849fe192bf5dfd124b7702bc",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://www.rfc-editor.org/rfc/rfc8956.html#section-5",
      "source": "cve@mitre.org"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
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      "description": [
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          "value": "CWE-1284"
        }
      ]
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  "descriptions": [
    {
      "lang": "en",
      "value": "An IPv6 FlowSpec validation bypass in the CZ.NIC BIRD Internet Routing Daemon allows an established BGP peer to inject FlowSpec rules matching destinations outside the address space authorized by the unicast-route validation procedure. With validation enabled on the receiving flow6 channel, BIRD fails to reject a destination prefix component with a nonzero offset, contrary to RFC 8956 section 5. It validates a reconstructed prefix with zero-filled skipped bits, although the original FlowSpec component can match a broader set of IPv6 addresses. Given a suitable unicast route from the peer, the rule can pass validation and, where export policy permits, be propagated to downstream peers. Downstream enforcement may cause unauthorized traffic filtering or redirection."
    }
  ],
  "lastModified": "2026-10-19T21:14:14.150",
  "sourceIdentifier": "cve@mitre.org"
}