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CVE Record

CVE-2026-2769: Use-after-free in the Storage: IndexedDB component

Use-after-free in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

HighCVSS 8.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-2769 is a high-severity Mozilla memory safety flaw in IndexedDB storage handling. A user running a vulnerable Firefox or Thunderbird build could be exposed through attacker-controlled content requiring user interaction. Mozilla lists fixed releases for Firefox, Firefox ESR, and Thunderbird.

Executive priority

Prioritize routine emergency patching for user workstations and managed Linux fleets. This is not confirmed as actively exploited in the provided sources, but browser-class memory corruption with high CVSS impact warrants fast remediation.

Technical view

The issue is a CWE-416 use-after-free in Mozilla's Storage: IndexedDB component. The CVSS 3.1 score is 8.8: network attack vector, low complexity, no privileges, user interaction required, with high confidentiality, integrity, and availability impact.

Likely exposure

Exposure is most likely on endpoints using Firefox, Firefox ESR, or Thunderbird before the Mozilla fixed versions: Firefox 148, ESR 115.33, ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Exploitation context

The source bundle does not show CISA KEV listing or cited evidence of active exploitation. It also does not provide exploit mechanics. Risk remains high because browser and mail-client memory corruption issues can affect many user endpoints.

Researcher notes

Focus validation on version and package provenance, not exploit reproduction. The provided record identifies the component, CWE, CVSS vector, and fixed versions, but does not disclose public exploit details or compensating controls beyond vendor updates.

Mitigation direction

  • Update Firefox to the fixed Mozilla release listed for your channel.
  • Update Firefox ESR to 115.33 or 140.8 where applicable.
  • Update Thunderbird to 148 or 140.8 where applicable.
  • Review Red Hat errata if using Mozilla packages from Red Hat.
  • Monitor Mozilla and OS vendor advisories for revised guidance.

Validation and detection

  • Inventory Firefox, Firefox ESR, and Thunderbird versions across managed endpoints.
  • Confirm deployed versions match or exceed the fixed releases in Mozilla advisories.
  • Check Linux package status against relevant Red Hat errata when applicable.
  • Verify vulnerability scanners recognize the installed fixed package versions.
  • Review exception lists for endpoints blocked from browser or mail-client updates.
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.

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cve · low confidence lookup

CVE-2026-2769 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:N/AC:L/PR:N/UI:R/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
35Source 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:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9CISA-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

8.8High
CVSS 3.1 vector shape for CVE-2026-2769Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

    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: Use-after-free in the Storage: IndexedDB component
other:Red Hat severity ratingcvssV3_1
  • 2026-02-24T14:02:40.379Z: Reported to Red Hat.
  • 2026-02-24T13:33:06.912Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox115.33, 140.8, 148Listed
MozillaThunderbird140.8, 148Listed
Weakness

CWE details

CWE-416

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