Security readout for executives and security teams
Plain-English summary
CVE-2026-6507 can let an unauthenticated remote attacker crash a dnsmasq service that uses DHCP split-relay mode. The resulting outage could disrupt DHCP-dependent network operations. The supplied data rates it high severity, but exposure depends on a specific configuration and reachable BOOTREPLY traffic.
Executive priority
Treat this as a high-priority availability issue for DHCP infrastructure using split-relay mode. Rapidly identify exposed configurations and reduce packet reachability. Broader emergency action is not supported because active exploitation is unconfirmed, affected-version information is inconsistent, and the listed Red Hat products are assessed as unaffected.
Technical view
A specially crafted BOOTREPLY packet can trigger an out-of-bounds write in dnsmasq DHCP bootreply processing when `--dhcp-split-relay` is enabled. Memory corruption can terminate the daemon, causing denial of service. The CVSS 3.1 score is 7.5, reflecting network reachability, low complexity, no privileges, and high availability impact.
Likely exposure
Likely exposure is limited to dnsmasq deployments using `--dhcp-split-relay` and accepting relevant BOOTREPLY packets from an attacker-reachable network path. The bundle mentions dnsmasq 2.92 but marks its default status unaffected, so affected-version boundaries are unclear. Listed Red Hat products are marked unaffected.
Exploitation context
The vulnerability requires a crafted BOOTREPLY packet reaching a specifically configured dnsmasq service. No user interaction or authentication is indicated. The bundle says this CVE is not in KEV and provides no evidence of active exploitation, public exploitation, or successful impact beyond daemon crash and denial of service.
Researcher notes
The documented weakness is CWE-787 in DHCP bootreply processing, with availability as the stated impact. Source data does not establish confidentiality or integrity consequences. Version scope needs clarification: dnsmasq 2.92 appears in the affected array while its default status says unaffected. No patch version, commit, or vendor mitigation is supplied.
Mitigation direction
- Check current dnsmasq vendor guidance for confirmed affected versions and any available update.
- Disable `--dhcp-split-relay` where the feature is unnecessary and operationally safe to remove.
- Restrict BOOTREPLY traffic to trusted relay paths as an interim exposure reduction.
- Prioritize resilience and service-restart controls for DHCP infrastructure pending authoritative remediation guidance.
Validation and detection
- Inventory dnsmasq versions across DHCP servers, appliances, containers, and embedded network systems.
- Identify every deployment configured with `--dhcp-split-relay`.
- Verify whether untrusted networks can deliver BOOTREPLY traffic to those services.
- Review dnsmasq crashes, abnormal restarts, and memory-corruption indicators without assuming they prove exploitation.
- Confirm listed Red Hat deployments against Red Hat's current CVE assessment.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-787: 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.
Open ATT&CK lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-6507 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
SSVC decision data
CVSS vector scores
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhatVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- Source timelineredhat
Reported to Red Hat.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Source timelineredhat
Made public.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://access.redhat.com/security/cve/CVE-2026-6507CVE reference, redhat · vdb-entry, x_refsource_REDHAT
- RHBZ#2459181CVE reference, redhat · issue-tracking, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.