Vulnerability-Lookup

UBUNTU-CVE-2026-14586 (CVE-2026-14586)

Vulnerability from osv_ubuntu – Published: 2026-07-22 14:17 – Updated: 2026-10-21 13:54 – Source website

Details

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, in DNS-over-QUIC environments, with high concurrency and under pressure, an assertion in libngtcp2 about monotonic timestamps could trigger and result in server termination and thus denial of service. When interfacing with libngtcp2, for DNS-over-QUIC support in Unbound, it is expected to use monotonic time. Unbound was using realtime instead, and in DoQ environments with high concurrency and under pressure, an assert in libngtcp2 for the quic timestamp would trigger and terminate the server.This vulnerability needs Unbound to be compiled with DoQ support ('--with-libngtcp2') and the 'quic-port' to be configured for the listening interfaces.

Severity

5.9 (Medium)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-14586	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-14586	REPORT
	https://community.nlnetlabs.nl/t/unbound-1-25-2-r…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libunbound2",
            "binary_version": "1.4.22-1ubuntu4.14.04.3+esm5"
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        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "unbound",
        "purl": "pkg:deb/ubuntu/unbound@1.4.22-1ubuntu4.14.04.3+esm5?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
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        "1.4.21-1",
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        "1.4.22-1ubuntu4",
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          {
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    {
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      ]
    },
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          },
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            "binary_name": "unbound-anchor",
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      },
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        "1.19.2-1ubuntu3.5",
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            "binary_name": "unbound-anchor",
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          },
          {
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      },
      "package": {
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        "1.24.2-1ubuntu2.2",
        "1.24.2-1ubuntu2.3",
        "1.24.2-1ubuntu2.4"
      ]
    }
  ],
  "aliases": [],
  "details": "In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, in DNS-over-QUIC environments, with high concurrency and under pressure, an assertion in libngtcp2 about monotonic timestamps could trigger and result in server termination and thus denial of service. When interfacing with libngtcp2, for DNS-over-QUIC support in Unbound, it is expected to use monotonic time. Unbound was using realtime instead, and in DoQ environments with high concurrency and under pressure, an assert in libngtcp2 for the quic timestamp would trigger and terminate the server.This vulnerability needs Unbound to be compiled with DoQ support (\u0027--with-libngtcp2\u0027) and the \u0027quic-port\u0027 to be configured for the listening interfaces.",
  "id": "UBUNTU-CVE-2026-14586",
  "modified": "2026-10-21T13:54:48Z",
  "published": "2026-07-22T14:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-14586"
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    },
    {
      "type": "REPORT",
      "url": "https://community.nlnetlabs.nl/t/unbound-1-25-2-released/3430"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-14586"
  ]
}

CVE-2026-14586 (GCVE-0-2026-14586)

Vulnerability from cvelistv5 – Published: 2026-07-22 13:03 – Updated: 2026-07-22 14:33

Title

Assertion in libngtcp2 when under pressure in high concurrency DNS-over-QUIC environments

Summary

Severity

5.9 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-22 14:32 UTC

CWE

CWE-617 - Reachable Assertion

Assigner

NLnet Labs CNA

CNA scorecard B 82/100 over 66 records in the last 180 days details

References

1 reference

URL	Tags
https://www.nlnetlabs.nl/downloads/unbound/CVE-20…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
NLnet Labs	Unbound	Affected: 1.22.0 , < 1.25.2 (semver)

Date Public

2026-07-22 00:00

Credits

Kunta Chu (Tsinghua University) Kaihua Wang (Tsinghua University) Jianjun Chen (Tsinghua University)

Show details on NVD website

JSON

To clipboard

{
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                "id": "CVE-2026-14586",
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    "assignerOrgId": "206fc3a0-e175-490b-9eaa-a5738056c9f6",
    "assignerShortName": "NLnet Labs",
    "cveId": "CVE-2026-14586",
    "datePublished": "2026-07-22T13:03:53.107Z",
    "dateReserved": "2026-07-03T11:59:36.383Z",
    "dateUpdated": "2026-07-22T14:33:23.363Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

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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.

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