Vulnerability-Lookup

CVE-2026-26018 (GCVE-0-2026-26018)

Vulnerability from cvelistv5 – Published: 2026-03-06 15:35 – Updated: 2026-07-09 12:09

Title

CoreDNS Loop Detection Denial of Service Vulnerability

Summary

CoreDNS is a DNS server that chains plugins. Prior to version 1.14.2, a denial of service vulnerability exists in CoreDNS's loop detection plugin that allows an attacker to crash the DNS server by sending specially crafted DNS queries. The vulnerability stems from the use of a predictable pseudo-random number generator (PRNG) for generating a secret query name, combined with a fatal error handler that terminates the entire process. This issue has been patched in version 1.14.2.

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-337 - Predictable Seed in Pseudo-Random Number Generator (PRNG)
CWE-770 - Allocation of Resources Without Limits or Throttling
CWE-400 - Uncontrolled Resource Consumption
CWE-1241 - Use of Predictable Algorithm in Random Number Generator

Assigner

GitHub_M

References

8 references

URL	Tags
https://github.com/coredns/coredns/security/advis…	x_refsource_CONFIRM
https://github.com/coredns/coredns/releases/tag/v1.14.2	x_refsource_MISC
https://access.redhat.com/security/cve/CVE-2026-26018	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2445242	issue-trackingx_refsource_REDHAT
https://security.access.redhat.com/data/csaf/v2/v…	x_sadp-csaf-vex
https://access.redhat.com/errata/RHSA-2026:36873	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:25127	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:8151	vendor-advisoryx_refsource_REDHAT

Impacted products

6 products

Vendor	Product	Version
coredns	coredns	Affected: < 1.14.2
Red Hat	Red Hat Advanced Cluster Management for Kubernetes 2.13	cpe:/a:redhat:acm:2.13::el9
Red Hat	Red Hat Advanced Cluster Management for Kubernetes 2.14	cpe:/a:redhat:acm:2.14::el9
Red Hat	Red Hat Advanced Cluster Management for Kubernetes 2.15	cpe:/a:redhat:acm:2.15::el9
Red Hat	Red Hat Connectivity Link 1	cpe:/a:redhat:connectivity_link:1
Red Hat	Red Hat OpenShift Container Platform 4	cpe:/a:redhat:openshift:4

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      "dataVersion": "5.2"
    }
  }
}

WID-SEC-W-2026-0627

Vulnerability from csaf_certbund - Published: 2026-03-05 23:00 - Updated: 2026-06-10 22:00

Summary

CoreDNS: Mehrere Schwachstellen

Severity

Mittel

Notes

Das BSI ist als Anbieter für die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch dafür verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgfältig im Einzelfall zu prüfen.

Produktbeschreibung: CoreDNS ist ein DNS server.

Angriff: Ein Angreifer kann mehrere Schwachstellen in CoreDNS ausnutzen, um Sicherheitsvorkehrungen zu umgehen, und um einen Denial of Service Angriff durchzuführen.

Betroffene Betriebssysteme: - Linux - UNIX

CVE-2026-26017

Affected products

Known affected 4 products

Product	Identifier	Version
Red Hat Enterprise Linux Red Hat	`cpe:/o:redhat:enterprise_linux:-`	—
SUSE openSUSE SUSE	`cpe:/o:suse:opensuse:-`	—
Open Source CoreDNS <1.14.2 Open Source / CoreDNS		<1.14.2
Microsoft Azure Linux azl3 Microsoft / Azure Linux	`cpe:/o:microsoft:azure_linux:azl3`	azl3

CVE-2026-26018

Affected products

Known affected 4 products

Product	Identifier	Version
Red Hat Enterprise Linux Red Hat	`cpe:/o:redhat:enterprise_linux:-`	—
SUSE openSUSE SUSE	`cpe:/o:suse:opensuse:-`	—
Open Source CoreDNS <1.14.2 Open Source / CoreDNS		<1.14.2
Microsoft Azure Linux azl3 Microsoft / Azure Linux	`cpe:/o:microsoft:azure_linux:azl3`	azl3

References

10 references

URL	Category
https://wid.cert-bund.de/.well-known/csaf/white/2…	self
https://wid.cert-bund.de/portal/wid/securityadvis…	self
https://github.com/coredns/coredns/security/advis…	external
https://github.com/coredns/coredns/security/advis…	external
https://lists.opensuse.org/archives/list/security…	external
https://msrc.microsoft.com/update-guide/	external
https://lists.opensuse.org/archives/list/security…	external
https://lists.opensuse.org/archives/list/security…	external
https://lists.opensuse.org/archives/list/security…	external
https://access.redhat.com/errata/RHSA-2026:25127	external

JSON

To clipboard

{
  "document": {
    "aggregate_severity": {
      "text": "mittel"
    },
    "category": "csaf_base",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "de-DE",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "Das BSI ist als Anbieter f\u00fcr die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch daf\u00fcr verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgf\u00e4ltig im Einzelfall zu pr\u00fcfen."
      },
      {
        "category": "description",
        "text": "CoreDNS ist ein DNS server.",
        "title": "Produktbeschreibung"
      },
      {
        "category": "summary",
        "text": "Ein Angreifer kann mehrere Schwachstellen in CoreDNS ausnutzen, um Sicherheitsvorkehrungen zu umgehen, und um einen Denial of Service Angriff durchzuf\u00fchren.",
        "title": "Angriff"
      },
      {
        "category": "general",
        "text": "- Linux\n- UNIX",
        "title": "Betroffene Betriebssysteme"
      }
    ],
    "publisher": {
      "category": "other",
      "contact_details": "csaf-provider@cert-bund.de",
      "name": "Bundesamt f\u00fcr Sicherheit in der Informationstechnik",
      "namespace": "https://www.bsi.bund.de"
    },
    "references": [
      {
        "category": "self",
        "summary": "WID-SEC-W-2026-0627 - CSAF Version",
        "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0627.json"
      },
      {
        "category": "self",
        "summary": "WID-SEC-2026-0627 - Portal Version",
        "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0627"
      },
      {
        "category": "external",
        "summary": "CoreDNS GitHub vom 2026-03-05",
        "url": "https://github.com/coredns/coredns/security/advisories/GHSA-c9v3-4pv7-87pr"
      },
      {
        "category": "external",
        "summary": "CoreDNS GitHub vom 2026-03-05",
        "url": "https://github.com/coredns/coredns/security/advisories/GHSA-h75p-j8xm-m278"
      },
      {
        "category": "external",
        "summary": "openSUSE Security Update OPENSUSE-SU-2026:10297-1 vom 2026-03-08",
        "url": "https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/XTKYCU7PQZZIHLVJXWGEMRKJRO3UY3UT/"
      },
      {
        "category": "external",
        "summary": "Microsoft Leitfaden f\u00fcr Sicherheitsupdates vom 2026-03-10",
        "url": "https://msrc.microsoft.com/update-guide/"
      },
      {
        "category": "external",
        "summary": "openSUSE Security Update OPENSUSE-SU-2026:0079-1 vom 2026-03-11",
        "url": "https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/AHRCSJENZA3STN62UKMLBRZ4QP3KV22D/"
      },
      {
        "category": "external",
        "summary": "openSUSE Security Update OPENSUSE-SU-2026:0080-1 vom 2026-03-11",
        "url": "https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/DPID4P33S2DUNWVEUQAOMM2IL347ZUIU/"
      },
      {
        "category": "external",
        "summary": "openSUSE Security Update OPENSUSE-SU-2026:20619-1 vom 2026-04-24",
        "url": "https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/XUWFAM7PG7C5B2EEMQCBNZCSTIRS4EOJ/"
      },
      {
        "category": "external",
        "summary": "Red Hat Security Advisory RHSA-2026:25127 vom 2026-06-11",
        "url": "https://access.redhat.com/errata/RHSA-2026:25127"
      }
    ],
    "source_lang": "en-US",
    "title": "CoreDNS: Mehrere Schwachstellen",
    "tracking": {
      "current_release_date": "2026-06-10T22:00:00.000+00:00",
      "generator": {
        "date": "2026-06-11T10:51:56.779+00:00",
        "engine": {
          "name": "BSI-WID",
          "version": "1.6.0"
        }
      },
      "id": "WID-SEC-W-2026-0627",
      "initial_release_date": "2026-03-05T23:00:00.000+00:00",
      "revision_history": [
        {
          "date": "2026-03-05T23:00:00.000+00:00",
          "number": "1",
          "summary": "Initiale Fassung"
        },
        {
          "date": "2026-03-08T23:00:00.000+00:00",
          "number": "2",
          "summary": "Neue Updates von openSUSE und European Union Vulnerability Database aufgenommen"
        },
        {
          "date": "2026-03-10T23:00:00.000+00:00",
          "number": "3",
          "summary": "Neue Updates aufgenommen"
        },
        {
          "date": "2026-03-11T23:00:00.000+00:00",
          "number": "4",
          "summary": "Neue Updates von openSUSE aufgenommen"
        },
        {
          "date": "2026-04-26T22:00:00.000+00:00",
          "number": "5",
          "summary": "Neue Updates von openSUSE aufgenommen"
        },
        {
          "date": "2026-06-10T22:00:00.000+00:00",
          "number": "6",
          "summary": "Neue Updates von Red Hat aufgenommen"
        }
      ],
      "status": "final",
      "version": "6"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "azl3",
                "product": {
                  "name": "Microsoft Azure Linux azl3",
                  "product_id": "T049210",
                  "product_identification_helper": {
                    "cpe": "cpe:/o:microsoft:azure_linux:azl3"
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            "category": "product_name",
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        "category": "vendor",
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      {
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          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c1.14.2",
                "product": {
                  "name": "Open Source CoreDNS \u003c1.14.2",
                  "product_id": "T051469"
                }
              },
              {
                "category": "product_version",
                "name": "1.14.2",
                "product": {
                  "name": "Open Source CoreDNS 1.14.2",
                  "product_id": "T051469-fixed",
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                    "cpe": "cpe:/a:coredns:coredns:1.14.2"
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            "category": "product_name",
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        "category": "vendor",
        "name": "Open Source"
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        "branches": [
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            "category": "product_name",
            "name": "Red Hat Enterprise Linux",
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              "name": "Red Hat Enterprise Linux",
              "product_id": "67646",
              "product_identification_helper": {
                "cpe": "cpe:/o:redhat:enterprise_linux:-"
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        "category": "vendor",
        "name": "Red Hat"
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      {
        "branches": [
          {
            "category": "product_name",
            "name": "SUSE openSUSE",
            "product": {
              "name": "SUSE openSUSE",
              "product_id": "T027843",
              "product_identification_helper": {
                "cpe": "cpe:/o:suse:opensuse:-"
              }
            }
          }
        ],
        "category": "vendor",
        "name": "SUSE"
      }
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  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-26017",
      "product_status": {
        "known_affected": [
          "67646",
          "T027843",
          "T051469",
          "T049210"
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      },
      "release_date": "2026-03-05T23:00:00.000+00:00",
      "title": "CVE-2026-26017"
    },
    {
      "cve": "CVE-2026-26018",
      "product_status": {
        "known_affected": [
          "67646",
          "T027843",
          "T051469",
          "T049210"
        ]
      },
      "release_date": "2026-03-05T23:00:00.000+00:00",
      "title": "CVE-2026-26018"
    }
  ]
}

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.

Action not permitted

CVE-2026-26018 (GCVE-0-2026-26018)

WID-SEC-W-2026-0627

Tags

Sightings

Nomenclature