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CVE Record

CVE-2026-12297: Sandbox escape due to incorrect boundary conditions in the Networking component

Sandbox escape due to incorrect boundary conditions in the Networking 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-2026-12297 is a critical Mozilla sandbox escape in the Networking component. A user action is required, but successful exploitation could break out of intended isolation and affect confidentiality, integrity, and availability. Mozilla states the issue is fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

Executive priority

Treat this as urgent patch management for browser and email-client fleets. It is critical severity with full impact potential, but the provided sources do not show active exploitation. Prioritize systems used for internet browsing, email handling, and high-value administrative work.

Technical view

The CVE describes incorrect boundary conditions in Mozilla's Networking component causing a sandbox escape. CVSS 3.1 is 9.6 with network attack vector, low complexity, no privileges, required user interaction, changed scope, and high CIA impact. Mapped weaknesses are CWE-119 and CWE-653. Public details do not provide exploit mechanics.

Likely exposure

Exposure is most likely where Firefox or Thunderbird installations are not confirmed at Mozilla's fixed versions, including enterprise Linux packages tracked through Red Hat advisories. Validate both desktop fleets and managed server images that include browser or mail client packages.

Exploitation context

The bundle does not show CISA KEV listing or any cited evidence of active exploitation. The CVSS vector indicates remote reachability with user interaction required. Because this is a sandbox escape, risk increases when paired with another browser or content-processing bug, but no chain is documented here.

Researcher notes

Public information is limited to high-level vulnerability metadata, affected Mozilla products, fixed versions, CVSS, CWE mappings, Bugzilla, Mozilla advisories, and Red Hat tracking. Avoid assuming exploitability details beyond UI-required remote attack and sandbox escape impact. No weaponization indicators are present in the bundle.

Mitigation direction

  • Upgrade Firefox to 152, ESR 140.12, or ESR 115.37 as applicable.
  • Upgrade Thunderbird to 152 or 140.12 as applicable.
  • Apply relevant Red Hat security errata for affected enterprise packages.
  • Enforce managed update completion and application restarts.
  • If updates are delayed, reduce exposure to untrusted web and email content.

Validation and detection

  • Inventory Firefox and Thunderbird versions across endpoints and images.
  • Confirm installed versions match Mozilla's fixed release numbers.
  • Check Red Hat advisory applicability for subscribed systems.
  • Verify update deployment reports include restart or relaunch completion.
  • Monitor vendor advisories for revised scope or exploit information.
Prepared
Confidence
high
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-119: 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-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
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-2026-12297 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-2026-12297Attack 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 due to incorrect boundary conditions in the Networking component
other:Red Hat severity ratingcvssV3_1
  • 2026-06-16T14:02:19.065Z: Reported to Red Hat.
  • 2026-06-16T11:52:30.907Z: 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-119CWE-653

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