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CVE Record

CVE-2026-4688: Sandbox escape due to use-after-free in the Disability Access APIs component

Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CriticalCVSS 9.6Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

CVE-2026-4688 is a critical Mozilla sandbox escape involving memory misuse in Disability Access APIs. A victim likely must interact with malicious content, but successful exploitation could break browser or mail-client isolation and enable serious compromise. Mozilla lists fixes in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Executive priority

Treat this as urgent endpoint patching. The business risk is high because browsers and mail clients are widely exposed, and sandbox escapes can turn ordinary content handling into broader system compromise when chained with other flaws.

Technical view

The issue is a use-after-free, with CWE-416 and CWE-825 mappings, in Mozilla's Disability Access APIs component. CVSS 3.1 is 9.6 with network attack vector, low complexity, no privileges, required user interaction, changed scope, and high confidentiality, integrity, and availability impact.

Likely exposure

Exposure is most likely on endpoints running unfixed Firefox, Firefox ESR, Thunderbird, or downstream Red Hat-packaged Mozilla builds. The source bundle does not define every vulnerable prior version, so version validation must use Mozilla and operating-system vendor advisories.

Exploitation context

The source bundle does not show CISA KEV listing or active exploitation evidence. The CVSS vector indicates remote delivery with user interaction, consistent with malicious web or message content risk, but no exploit chain or weaponized details are provided.

Researcher notes

Bugzilla is referenced, but the bundle provides limited technical detail. Do not assume active exploitation, affected pre-release ranges, or mitigations beyond vendor updates. Focus validation on installed product versions, downstream packaging status, and whether fixed Mozilla or Red Hat builds are deployed.

Mitigation direction

  • Update Firefox to 149 or Firefox ESR to 140.9 or later.
  • Update Thunderbird to 149 or 140.9 or later.
  • Apply applicable Red Hat security advisories for managed Linux builds.
  • Prioritize patching browsers and mail clients on high-risk workstations.
  • Check Mozilla and OS vendor guidance for any additional mitigations.

Validation and detection

  • Inventory Firefox, Firefox ESR, and Thunderbird versions across endpoints.
  • Confirm patched versions match Mozilla fixed-release guidance.
  • Map Red Hat systems to listed RHSA advisories and update status.
  • Review endpoint management telemetry for failed or deferred browser updates.
  • Check security logs for unusual browser or mail-client crashes around disclosure.
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-416: 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-825: 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-2026-4688 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
34Source 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-2026-4688Attack 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 use-after-free in the Disability Access APIs component
other:Red Hat severity ratingcvssV3_1
  • 2026-03-24T13:01:30.214Z: Reported to Red Hat.
  • 2026-03-24T12:30:22.710Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox140.9, 149Listed
MozillaThunderbird140.9, 149Listed
Weakness

CWE details

CWE-416CWE-825

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

CWE-416 · source CWE mapping

Use After Free

Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-825 · source CWE mapping

Expired Pointer Dereference

Expired Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs