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CVE Record

CVE-2026-4892: CVE-2026-4892

A heap-based out-of-bounds write vulnerability in the DHCPv6 implementation of dnsmasq allows local attackers to execute arbitrary code with root privileges via a crafted DHCPv6 packet.

HighCVSS 8.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A nearby network attacker could send a malicious DHCPv6 packet to a vulnerable dnsmasq service and potentially take full control of the device as root. Successful exploitation could expose data, alter configurations, disrupt networking, or provide a foothold into connected environments.

Executive priority

Address promptly, beginning with DHCPv6-enabled infrastructure exposed to guest, shared, or otherwise untrusted local networks. Root-level code execution makes successful compromise severe, although adjacent-network access limits reach compared with an internet-routable flaw. Do not defer solely because active exploitation is unconfirmed.

Technical view

CVE-2026-4892 is a heap-based out-of-bounds write in dnsmasq’s DHCPv6 implementation. It requires adjacent-network access, but no authentication or user interaction. The supplied CVSS 3.1 score is 8.8, with potentially complete confidentiality, integrity, and availability impact. The precise affected version range is not established in the supplied data.

Likely exposure

Prioritize devices running dnsmasq with DHCPv6 enabled and reachable from untrusted or shared local networks. Routers, network appliances, Linux systems, and bundled products may warrant review, but the supplied evidence does not establish which specific versions or downstream packages are vulnerable.

Exploitation context

The CVSS vector indicates low-complexity exploitation from an adjacent network without credentials or user interaction. The supplied bundle marks this CVE as absent from KEV and provides no cited evidence of active exploitation. Treat proof-of-concept availability and real-world exploitation status as unconfirmed.

Researcher notes

The supplied affected-version entry lists only “0,” which is insufficient for reliable version scoping. Confirm vulnerable and fixed versions through upstream or distributor advisories. The described primitive is a heap out-of-bounds write classified as CWE-122. No exploitability prerequisites beyond the CVSS vector should be inferred from this bundle.

Mitigation direction

  • Identify dnsmasq deployments and determine whether DHCPv6 is enabled or reachable.
  • Apply fixes provided by dnsmasq or the relevant operating-system and appliance vendors.
  • Review the cited Red Hat advisories for applicable supported packages and updates.
  • Check downstream product guidance, including Pi-hole, before applying product-specific releases.
  • Restrict untrusted access to DHCPv6 services where operationally feasible.

Validation and detection

  • Record installed dnsmasq and downstream package versions on potentially exposed systems.
  • Confirm DHCPv6 configuration and adjacent-network reachability for each deployment.
  • Compare installed packages against applicable upstream and vendor advisories.
  • Verify updated package versions after remediation and restart affected services if vendor guidance requires it.
  • Monitor vendor notices because the supplied affected-version value is incomplete.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-122: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-4892 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.8 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
15Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.8CVSS 3.1HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H2.85.9redhat-SADP
8.4CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H2.55.9CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

8.8High
CVSS 3.1 vector shape for CVE-2026-4892Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc
redhat-SADPdnsmasq: DHCPv6 CLID buffer overflow in helper process
other:Red Hat severity ratingcvssV3_1
  • 2026-04-14T22:44:58.432Z: Reported to Red Hat.
  • 2026-05-09T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
dnsmasqdnsmasq0Listed
Weakness

CWE details

CWE-122

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-122 · source CWE mapping

Heap-based Buffer Overflow

Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs