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CVE Record

CVE-2026-12295: Sandbox escape in the DOM: Navigation component

Sandbox escape in the DOM: Navigation component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

CriticalCVSS 9.6Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

CVE-2026-12295 is a critical Mozilla sandbox escape in the DOM Navigation component. A user interaction is required, but successful exploitation could break expected browser or mail-client isolation and affect confidentiality, integrity, and availability. Mozilla says it is fixed in listed Firefox and Thunderbird releases.

Executive priority

Treat this as urgent endpoint patching. The issue has critical impact and affects common client software, but the provided evidence does not show known active exploitation. Prioritize remediation within critical vulnerability SLAs, especially for internet-facing user workstations.

Technical view

The CVSS 3.1 vector is 9.6: network reachable, low complexity, no privileges, user interaction required, changed scope, and high CIA impact. The listed weaknesses are CWE-653 and CWE-693, indicating security mechanism or protection failures. Public details in the bundle do not describe the vulnerable code path.

Likely exposure

Exposure is likely on endpoints running Mozilla Firefox or Thunderbird that have not been updated to the fixed versions named by Mozilla or vendor packages referenced by Red Hat. The bundle does not provide precise vulnerable version ranges beyond the fixed release information.

Exploitation context

The CVE is not marked as CISA KEV, and the provided sources do not cite active exploitation. The attack model still matters because exploitation is network-originated and requires only user interaction, typical of browser or email-client risk.

Researcher notes

Public detail is limited in the bundle. Bugzilla and advisory references identify a DOM Navigation sandbox escape and fixed product releases, but do not provide enough evidence to validate root cause safely from public data alone. Avoid assuming exploitability beyond the CVSS vector and advisory language.

Mitigation direction

  • Update Firefox to Mozilla's fixed release for your supported channel.
  • Update Thunderbird to Mozilla's fixed release for your supported channel.
  • Apply relevant Red Hat security advisories where Firefox or Thunderbird comes from Red Hat packages.
  • Check Mozilla and OS vendor guidance for any channel-specific instructions.
  • Prioritize endpoints that browse untrusted sites or process external email.

Validation and detection

  • Inventory installed Firefox and Thunderbird versions across managed endpoints.
  • Compare installed versions against Mozilla's fixed releases in the advisory.
  • Check Linux package versions against applicable Red Hat errata.
  • Confirm endpoint management reports show completed browser and mail-client updates.
  • Review vulnerability scanner findings for CVE-2026-12295 after patch deployment.
Prepared
Confidence
medium
Sources
12

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-653: 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 lookup
cwe · low confidence lookup

CWE-693: 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 lookup
description · low confidence lookup

Privilege behavior lookup

The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. 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-2026-12295 mapping review

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

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.6 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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
22Source 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
9.6CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H2.86CISA-ADP
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H1.65.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

9.6Critical
CVSS 3.1 vector shape for CVE-2026-12295Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  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-SADPfirefox: thunderbird: Sandbox escape in the DOM: Navigation component
other:Red Hat severity ratingcvssV3_1
  • 2026-06-16T14:01:52.693Z: Reported to Red Hat.
  • 2026-06-16T11:52:28.892Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox115.37, 140.12, 152Listed
MozillaThunderbird140.12, 152Listed
Weakness

CWE details

CWE-653CWE-693

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