Vulnerability-Lookup

CVE-2026-62994 (GCVE-0-2026-62994)

Vulnerability from cvelistv5 – Published: 2026-07-16 19:39 – Updated: 2026-07-17 11:12

Title

CoreDNS `k8s_external` headless AXFR can emit an empty transfer batch that panics the `transfer` plugin

Summary

CoreDNS is a DNS server written in Go. From 1.9.4 until 1.14.5, a network DNS client allowed to request AXFR for a CoreDNS zone can trigger a panic when CoreDNS is configured with k8s_external headless-service zone transfers and Kubernetes contains a headless service endpoint with no declared ports; plugin/kubernetes/object/endpoint.go creates Port: -1, plugin/k8s_external/msg_to_dns.go skips that service, plugin/k8s_external/transfer.go sends an empty []dns.RR batch, and plugin/transfer/transfer.go indexes records[0] without checking the batch is non-empty. This issue is fixed in version 1.14.5.

Severity

3.7 (Low)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-17 11:12 UTC

CWE

CWE-248 - Uncaught Exception
CWE-755 - Improper Handling of Exceptional Conditions

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 8129 records in the last 180 days details

References

4 references

URL	Tags
https://github.com/coredns/coredns/security/advis…	x_refsource_CONFIRM
https://github.com/coredns/coredns/pull/8207	x_refsource_MISC
https://github.com/coredns/coredns/commit/ab318db…	x_refsource_MISC
https://github.com/coredns/coredns/releases/tag/v1.14.5	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
coredns	coredns	Affected: >= 1.9.4, < 1.14.5	guessed

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-62994

Vulnerability from fkie_nvd - Published: 2026-07-16 20:16 - Updated: 2026-07-22 20:14

Severity

3.7 (Low) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Summary

References

URL	Tags
security-advisories@github.com	https://github.com/coredns/coredns/commit/ab318db7b4a3a19273852ed627f54888198c8efb	Patch
security-advisories@github.com	https://github.com/coredns/coredns/pull/8207	Issue Tracking, Patch
security-advisories@github.com	https://github.com/coredns/coredns/releases/tag/v1.14.5	Release Notes
security-advisories@github.com	https://github.com/coredns/coredns/security/advisories/GHSA-74w3-63xv-x9mv	Exploit, Third Party Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/coredns/coredns/security/advisories/GHSA-74w3-63xv-x9mv	Exploit, Third Party Advisory

Impacted products

	Vendor	Product	Version
	coredns.io	coredns	*

JSON

To clipboard

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  "lastModified": "2026-07-22T20:14:36.067",
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    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/coredns/coredns/commit/ab318db7b4a3a19273852ed627f54888198c8efb"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "url": "https://github.com/coredns/coredns/pull/8207"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Release Notes"
      ],
      "url": "https://github.com/coredns/coredns/releases/tag/v1.14.5"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://github.com/coredns/coredns/security/advisories/GHSA-74w3-63xv-x9mv"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://github.com/coredns/coredns/security/advisories/GHSA-74w3-63xv-x9mv"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-248"
        },
        {
          "lang": "en",
          "value": "CWE-755"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

GHSA-74W3-63XV-X9MV

Vulnerability from github – Published: 2026-10-16 19:26 – Updated: 2026-10-16 19:26

Summary

CoreDNS `k8s_external` headless AXFR can emit an empty transfer batch that panics the `transfer` plugin

Details

Summary

A network DNS client allowed to request AXFR for a CoreDNS zone can trigger a panic when CoreDNS is configured with k8s_external headless-service zone transfers and Kubernetes contains a headless service endpoint with no declared ports. The built-in k8s_external transferer can emit an empty []dns.RR batch, and the shared transfer plugin indexes records[0] without checking that the batch is non-empty. In normal CoreDNS mode the panic is recovered and returned as SERVFAIL, but repeated triggering can disrupt requests and amplify panic logging; if the debug plugin disables recovery, the same path can crash the CoreDNS process.

Details

plugin/transfer/transfer.go assumes that every Transferer emits only non-empty []dns.RR batches. During AXFR/IXFR response generation it indexes records[0] without checking the slice length:

plugin/transfer/transfer.go:129-131

for records := range pchan {
    if x, ok := records[0].(*dns.SOA); ok && soa == nil {
        soa = x
    }

The built-in k8s_external transferer violates that contract for headless services whose endpoints have no declared ports. plugin/k8s_external/transfer.go sends the SRV result slice unconditionally:

plugin/k8s_external/transfer.go:104-106

recs, _ := e.srv(ctx, svcs, s)
ch <- recs

plugin/k8s_external/msg_to_dns.go intentionally skips services whose port is -1:

plugin/k8s_external/msg_to_dns.go:107-112

for _, s := range services {
    // Don't add the entry if the port is -1 (invalid). The kubernetes plugin uses port -1 when a service/endpoint
    // does not have any declared ports.
    if s.Port == -1 {
        continue
    }

The Kubernetes EndpointSlice conversion creates that sentinel when an EndpointSlice has no ports:

plugin/kubernetes/object/endpoint.go:62-66

if len(ends.Ports) == 0 {
    // Add sentinel if there are no ports.
    e.Subsets[0].Ports = []EndpointPort{{Port: -1}}

This creates a built-in source-to-sink chain:

Kubernetes EndpointSlice has ready addresses and no ports.
CoreDNS kubernetes converts it to an endpoint with Port: -1.
k8s_external with headless includes that service in transfer data.
k8s_external.Transfer sends an empty SRV []dns.RR batch.
transfer.ServeDNS indexes records[0] and panics.

Suggested remediation:

In plugin/transfer/transfer.go, skip or reject empty records batches before indexing records[0].
In plugin/k8s_external/transfer.go, only send recs when len(recs) > 0 in the headless endpoint and port/protocol paths.
Add regression tests covering Port: -1 headless services and empty transfer batches.

Example consumer-side guard:

for records := range pchan {
    if len(records) == 0 {
        continue
    }
    if x, ok := records[0].(*dns.SOA); ok && soa == nil {
        soa = x
    }
    ...
}

PoC

Safe local unit-level reproduction was performed. It does not contact external infrastructure and does not require a live Kubernetes cluster.

Reproducer A: the `transfer` sink panics on an empty batch

A temporary package test was added under plugin/transfer:

package transfer

import (
    "context"
    "fmt"
    "testing"

    "github.com/coredns/coredns/plugin/pkg/dnstest"
    "github.com/coredns/coredns/plugin/test"

    "github.com/miekg/dns"
)

type auditEmptyBatchTransferer struct{}

func (auditEmptyBatchTransferer) Transfer(zone string, serial uint32) (<-chan []dns.RR, error) {
    if zone != "example.org." {
        return nil, ErrNotAuthoritative
    }
    ch := make(chan []dns.RR, 3)
    ch <- []dns.RR{test.SOA(fmt.Sprintf("%s 100 IN SOA ns.dns.%s hostmaster.%s %d 7200 1800 86400 100", zone, zone, zone, 1))}
    ch <- []dns.RR{}
    close(ch)
    return ch, nil
}

func TestAuditEmptyTransferBatchPanics(t *testing.T) {
    tr := &Transfer{
        Transferers: []Transferer{auditEmptyBatchTransferer{}},
        xfrs:        []*xfr{{Zones: []string{"example.org."}, to: []string{"*"}}},
    }

    req := new(dns.Msg)
    req.SetQuestion("example.org.", dns.TypeAXFR)
    rec := dnstest.NewRecorder(&test.ResponseWriter{TCP: true})

    defer func() {
        if rec := recover(); rec == nil {
            t.Fatal("expected empty transfer batch to panic")
        }
    }()

    _, _ = tr.ServeDNS(context.Background(), rec, req)
}

Verification command and result:

$ go test ./plugin/transfer -run TestAuditEmptyTransferBatchPanics -count=1 -v
=== RUN   TestAuditEmptyTransferBatchPanics
--- PASS: TestAuditEmptyTransferBatchPanics (0.00s)
PASS
ok      github.com/coredns/coredns/plugin/transfer  0.005s

Reproducer B: the built-in `k8s_external` transferer emits the empty batch

A temporary package test was added under plugin/k8s_external:

package external

import (
    "testing"
    "time"

    "github.com/coredns/coredns/plugin/etcd/msg"
    "github.com/coredns/coredns/plugin/kubernetes"
    "github.com/coredns/coredns/request"

    "github.com/miekg/dns"
)

func TestAuditHeadlessNoPortTransferEmitsEmptyBatch(t *testing.T) {
    e := New()
    e.Zones = []string{"example.com."}
    e.headless = true
    e.externalAddrFunc = func(request.Request, bool) []dns.RR { return nil }
    e.externalSerialFunc = func(string) uint32 { return 1 }
    e.externalServicesFunc = func(string, bool) ([]msg.Service, map[string][]msg.Service) {
        return nil, map[string][]msg.Service{
            "/coredns/com/example/testns/headless/" + kubernetes.Endpoint: {{Host: "192.0.2.10", Port: -1, TTL: 5, Key: "/coredns/com/example/testns/headless/endpoint-a"}},
        }
    }

    ch, err := e.Transfer("example.com.", 0)
    if err != nil {
        t.Fatalf("Transfer returned error: %v", err)
    }

    deadline := time.After(time.Second)
    for {
        select {
        case batch, ok := <-ch:
            if !ok {
                t.Fatal("transfer closed before emitting an empty batch")
            }
            if len(batch) == 0 {
                return
            }
        case <-deadline:
            t.Fatal("timed out waiting for an empty batch")
        }
    }
}

Verification command and result:

$ go test ./plugin/k8s_external -run TestAuditHeadlessNoPortTransferEmitsEmptyBatch -count=1 -v
=== RUN   TestAuditHeadlessNoPortTransferEmitsEmptyBatch
--- PASS: TestAuditHeadlessNoPortTransferEmitsEmptyBatch (0.00s)
PASS
ok      github.com/coredns/coredns/plugin/k8s_external  0.012s

Additional focused verification:

$ go test ./plugin/transfer ./plugin/k8s_external ./plugin/kubernetes -run 'TestAudit|^$' -count=1 -v
ok      github.com/coredns/coredns/plugin/transfer  0.006s
ok      github.com/coredns/coredns/plugin/k8s_external  0.013s
ok      github.com/coredns/coredns/plugin/kubernetes    0.116s

Affected package suites:

$ go test ./plugin/transfer ./plugin/k8s_external ./plugin/kubernetes -count=1
ok      github.com/coredns/coredns/plugin/transfer  0.010s
ok      github.com/coredns/coredns/plugin/k8s_external  0.011s
ok      github.com/coredns/coredns/plugin/kubernetes    0.194s

Impact

A network client allowed to request AXFR for the affected zone can trigger a panic in CoreDNS when all prerequisites are present.

Required configuration/state:

example.com:53 {
    kubernetes cluster.local
    k8s_external example.com {
        headless
    }
    transfer example.com {
        to *
    }
}

Additional prerequisite:

The Kubernetes API state contains a headless-service endpoint represented by an EndpointSlice with ready addresses and no ports, producing CoreDNS msg.Service{Port: -1}.

In normal CoreDNS mode, core/dnsserver/server.go:267-279 recovers the panic and returns SERVFAIL, so this is a request-level availability issue and panic/log amplification issue. If the debug plugin is enabled, the server disables the recovery path and this can crash the CoreDNS process.

Severity

3.7 (Low)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.14.4"
      },
      "package": {
        "ecosystem": "Go",
        "name": "github.com/coredns/coredns"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.9.4"
            },
            {
              "fixed": "1.14.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-62994"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-248",
      "CWE-755"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-16T19:26:42Z",
    "nvd_published_at": "2026-07-16T20:16:47Z",
    "severity": "LOW"
  },
  "details": "### Summary\n\nA network DNS client allowed to request AXFR for a CoreDNS zone can trigger a panic when CoreDNS is configured with `k8s_external` headless-service zone transfers and Kubernetes contains a headless service endpoint with no declared ports. The built-in `k8s_external` transferer can emit an empty `[]dns.RR` batch, and the shared `transfer` plugin indexes `records[0]` without checking that the batch is non-empty. In normal CoreDNS mode the panic is recovered and returned as `SERVFAIL`, but repeated triggering can disrupt requests and amplify panic logging; if the `debug` plugin disables recovery, the same path can crash the CoreDNS process.\n\n### Details\n\n`plugin/transfer/transfer.go` assumes that every `Transferer` emits only non-empty `[]dns.RR` batches. During AXFR/IXFR response generation it indexes `records[0]` without checking the slice length:\n\n- `plugin/transfer/transfer.go:129-131`\n\n```go\nfor records := range pchan {\n    if x, ok := records[0].(*dns.SOA); ok \u0026\u0026 soa == nil {\n        soa = x\n    }\n```\n\nThe built-in `k8s_external` transferer violates that contract for headless services whose endpoints have no declared ports. `plugin/k8s_external/transfer.go` sends the SRV result slice unconditionally:\n\n- `plugin/k8s_external/transfer.go:104-106`\n\n```go\nrecs, _ := e.srv(ctx, svcs, s)\nch \u003c- recs\n```\n\n`plugin/k8s_external/msg_to_dns.go` intentionally skips services whose port is `-1`:\n\n- `plugin/k8s_external/msg_to_dns.go:107-112`\n\n```go\nfor _, s := range services {\n    // Don\u0027t add the entry if the port is -1 (invalid). The kubernetes plugin uses port -1 when a service/endpoint\n    // does not have any declared ports.\n    if s.Port == -1 {\n        continue\n    }\n```\n\nThe Kubernetes EndpointSlice conversion creates that sentinel when an EndpointSlice has no ports:\n\n- `plugin/kubernetes/object/endpoint.go:62-66`\n\n```go\nif len(ends.Ports) == 0 {\n    // Add sentinel if there are no ports.\n    e.Subsets[0].Ports = []EndpointPort{{Port: -1}}\n```\n\nThis creates a built-in source-to-sink chain:\n\n1. Kubernetes EndpointSlice has ready addresses and no ports.\n2. CoreDNS `kubernetes` converts it to an endpoint with `Port: -1`.\n3. `k8s_external` with `headless` includes that service in transfer data.\n4. `k8s_external.Transfer` sends an empty SRV `[]dns.RR` batch.\n5. `transfer.ServeDNS` indexes `records[0]` and panics.\n\nSuggested remediation:\n\n1. In `plugin/transfer/transfer.go`, skip or reject empty `records` batches before indexing `records[0]`.\n2. In `plugin/k8s_external/transfer.go`, only send `recs` when `len(recs) \u003e 0` in the headless endpoint and port/protocol paths.\n3. Add regression tests covering `Port: -1` headless services and empty transfer batches.\n\nExample consumer-side guard:\n\n```go\nfor records := range pchan {\n    if len(records) == 0 {\n        continue\n    }\n    if x, ok := records[0].(*dns.SOA); ok \u0026\u0026 soa == nil {\n        soa = x\n    }\n    ...\n}\n```\n\n### PoC\n\nSafe local unit-level reproduction was performed. It does not contact external infrastructure and does not require a live Kubernetes cluster.\n\n#### Reproducer A: the `transfer` sink panics on an empty batch\n\nA temporary package test was added under `plugin/transfer`:\n\n```go\npackage transfer\n\nimport (\n    \"context\"\n    \"fmt\"\n    \"testing\"\n\n    \"github.com/coredns/coredns/plugin/pkg/dnstest\"\n    \"github.com/coredns/coredns/plugin/test\"\n\n    \"github.com/miekg/dns\"\n)\n\ntype auditEmptyBatchTransferer struct{}\n\nfunc (auditEmptyBatchTransferer) Transfer(zone string, serial uint32) (\u003c-chan []dns.RR, error) {\n    if zone != \"example.org.\" {\n        return nil, ErrNotAuthoritative\n    }\n    ch := make(chan []dns.RR, 3)\n    ch \u003c- []dns.RR{test.SOA(fmt.Sprintf(\"%s 100 IN SOA ns.dns.%s hostmaster.%s %d 7200 1800 86400 100\", zone, zone, zone, 1))}\n    ch \u003c- []dns.RR{}\n    close(ch)\n    return ch, nil\n}\n\nfunc TestAuditEmptyTransferBatchPanics(t *testing.T) {\n    tr := \u0026Transfer{\n        Transferers: []Transferer{auditEmptyBatchTransferer{}},\n        xfrs:        []*xfr{{Zones: []string{\"example.org.\"}, to: []string{\"*\"}}},\n    }\n\n    req := new(dns.Msg)\n    req.SetQuestion(\"example.org.\", dns.TypeAXFR)\n    rec := dnstest.NewRecorder(\u0026test.ResponseWriter{TCP: true})\n\n    defer func() {\n        if rec := recover(); rec == nil {\n            t.Fatal(\"expected empty transfer batch to panic\")\n        }\n    }()\n\n    _, _ = tr.ServeDNS(context.Background(), rec, req)\n}\n```\n\nVerification command and result:\n\n```text\n$ go test ./plugin/transfer -run TestAuditEmptyTransferBatchPanics -count=1 -v\n=== RUN   TestAuditEmptyTransferBatchPanics\n--- PASS: TestAuditEmptyTransferBatchPanics (0.00s)\nPASS\nok  \tgithub.com/coredns/coredns/plugin/transfer\t0.005s\n```\n\n#### Reproducer B: the built-in `k8s_external` transferer emits the empty batch\n\nA temporary package test was added under `plugin/k8s_external`:\n\n```go\npackage external\n\nimport (\n    \"testing\"\n    \"time\"\n\n    \"github.com/coredns/coredns/plugin/etcd/msg\"\n    \"github.com/coredns/coredns/plugin/kubernetes\"\n    \"github.com/coredns/coredns/request\"\n\n    \"github.com/miekg/dns\"\n)\n\nfunc TestAuditHeadlessNoPortTransferEmitsEmptyBatch(t *testing.T) {\n    e := New()\n    e.Zones = []string{\"example.com.\"}\n    e.headless = true\n    e.externalAddrFunc = func(request.Request, bool) []dns.RR { return nil }\n    e.externalSerialFunc = func(string) uint32 { return 1 }\n    e.externalServicesFunc = func(string, bool) ([]msg.Service, map[string][]msg.Service) {\n        return nil, map[string][]msg.Service{\n            \"/coredns/com/example/testns/headless/\" + kubernetes.Endpoint: {{Host: \"192.0.2.10\", Port: -1, TTL: 5, Key: \"/coredns/com/example/testns/headless/endpoint-a\"}},\n        }\n    }\n\n    ch, err := e.Transfer(\"example.com.\", 0)\n    if err != nil {\n        t.Fatalf(\"Transfer returned error: %v\", err)\n    }\n\n    deadline := time.After(time.Second)\n    for {\n        select {\n        case batch, ok := \u003c-ch:\n            if !ok {\n                t.Fatal(\"transfer closed before emitting an empty batch\")\n            }\n            if len(batch) == 0 {\n                return\n            }\n        case \u003c-deadline:\n            t.Fatal(\"timed out waiting for an empty batch\")\n        }\n    }\n}\n```\n\nVerification command and result:\n\n```text\n$ go test ./plugin/k8s_external -run TestAuditHeadlessNoPortTransferEmitsEmptyBatch -count=1 -v\n=== RUN   TestAuditHeadlessNoPortTransferEmitsEmptyBatch\n--- PASS: TestAuditHeadlessNoPortTransferEmitsEmptyBatch (0.00s)\nPASS\nok  \tgithub.com/coredns/coredns/plugin/k8s_external\t0.012s\n```\n\nAdditional focused verification:\n\n```text\n$ go test ./plugin/transfer ./plugin/k8s_external ./plugin/kubernetes -run \u0027TestAudit|^$\u0027 -count=1 -v\nok  \tgithub.com/coredns/coredns/plugin/transfer\t0.006s\nok  \tgithub.com/coredns/coredns/plugin/k8s_external\t0.013s\nok  \tgithub.com/coredns/coredns/plugin/kubernetes\t0.116s\n```\n\nAffected package suites:\n\n```text\n$ go test ./plugin/transfer ./plugin/k8s_external ./plugin/kubernetes -count=1\nok  \tgithub.com/coredns/coredns/plugin/transfer\t0.010s\nok  \tgithub.com/coredns/coredns/plugin/k8s_external\t0.011s\nok  \tgithub.com/coredns/coredns/plugin/kubernetes\t0.194s\n```\n\n### Impact\n\nA network client allowed to request AXFR for the affected zone can trigger a panic in CoreDNS when all prerequisites are present.\n\nRequired configuration/state:\n\n```corefile\nexample.com:53 {\n    kubernetes cluster.local\n    k8s_external example.com {\n        headless\n    }\n    transfer example.com {\n        to *\n    }\n}\n```\n\nAdditional prerequisite:\n\n- The Kubernetes API state contains a headless-service endpoint represented by an EndpointSlice with ready addresses and no ports, producing CoreDNS `msg.Service{Port: -1}`.\n\nIn normal CoreDNS mode, `core/dnsserver/server.go:267-279` recovers the panic and returns `SERVFAIL`, so this is a request-level availability issue and panic/log amplification issue. If the `debug` plugin is enabled, the server disables the recovery path and this can crash the CoreDNS process.",
  "id": "GHSA-74w3-63xv-x9mv",
  "modified": "2026-10-16T19:26:42Z",
  "published": "2026-10-16T19:26:42Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/coredns/coredns/security/advisories/GHSA-74w3-63xv-x9mv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-62994"
    },
    {
      "type": "WEB",
      "url": "https://github.com/coredns/coredns/pull/8207"
    },
    {
      "type": "WEB",
      "url": "https://github.com/coredns/coredns/commit/ab318db7b4a3a19273852ed627f54888198c8efb"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/coredns/coredns"
    },
    {
      "type": "WEB",
      "url": "https://github.com/coredns/coredns/releases/tag/v1.14.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "CoreDNS `k8s_external` headless AXFR can emit an empty transfer batch that panics the `transfer` plugin"
}

MSRC_CVE-2026-62994

Vulnerability from csaf_microsoft - Published: 2026-07-23 01:02 - Updated: 2026-08-09 01:40

Summary

CoreDNS `k8s_external` headless AXFR can emit an empty transfer batch that panics the `transfer` plugin

Scope

1 vulnerability in this advisory, including CVE-2026-62994.

CVE-2026-62994

3.7 (Low)


                
                  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Fixed: 1 product Known affected: 2 products

https://learn.microsoft.com/en-us/azure/azure-linux/tutoria…

Open the full advisory

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-62994 (GCVE-0-2026-62994)

FKIE_CVE-2026-62994

GHSA-74W3-63XV-X9MV

Summary

Details

PoC

Reproducer A: the transfer sink panics on an empty batch

Reproducer B: the built-in k8s_external transferer emits the empty batch

Impact

MSRC_CVE-2026-62994

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour

Reproducer A: the `transfer` sink panics on an empty batch

Reproducer B: the built-in `k8s_external` transferer emits the empty batch