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CVE Record

CVE-2026-2447: Heap buffer overflow in libvpx

Heap buffer overflow in libvpx. This vulnerability was fixed in Firefox 147.0.4, Firefox ESR 140.7.1, Firefox ESR 115.32.1, Thunderbird 140.7.2, and Thunderbird 147.0.2.

HighCVSS 8.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-2447 is a high-severity heap buffer overflow in libvpx fixed by Mozilla in Firefox and Thunderbird updates. A successful attack could affect confidentiality, integrity, and availability, but the provided evidence indicates user interaction is required and does not show known active exploitation.

Executive priority

Treat this as a prompt patching item for browser and email client fleets. It is not marked as actively exploited in the provided sources, but the impact rating supports near-term remediation through normal emergency or accelerated update processes.

Technical view

The issue is classified as CWE-122 with CVSS 3.1 score 8.8: network attack vector, low complexity, no privileges, user interaction required, unchanged scope, and high CIA impact. Mozilla lists fixed Firefox and Thunderbird releases; Debian and Red Hat references indicate downstream distribution handling.

Likely exposure

Exposure is most likely on endpoints running Firefox, Firefox ESR, or Thunderbird versions older than the Mozilla fixed releases listed in the bundle. Systems using downstream Linux packages should verify vendor errata status rather than relying only on upstream Mozilla version numbers.

Exploitation context

The source bundle does not include exploit details, proof-of-concept status, or confirmed in-the-wild exploitation. KEV is false. Risk remains material because the flaw is memory corruption reachable over a network with user interaction and high impact if triggered.

Researcher notes

Do not infer broader libvpx product exposure from this bundle alone. The cited data supports Mozilla Firefox and Thunderbird fixes plus downstream Debian and Red Hat tracking. Bug details may be restricted, and no safe exploitability conclusion is possible from the provided material.

Mitigation direction

  • Update Firefox to 147.0.4 or relevant ESR fixed release.
  • Update Thunderbird to 147.0.2 or 140.7.2 as applicable.
  • Apply Debian and Red Hat security updates where those distributions provide packages.
  • Check Mozilla and OS vendor advisories for environment-specific guidance.
  • Prioritize managed endpoints where browsers or email clients are externally exposed to content.

Validation and detection

  • Inventory Firefox, Firefox ESR, and Thunderbird versions across endpoints.
  • Confirm deployed versions meet or exceed the fixed releases in Mozilla advisories.
  • Review Debian LTS and Red Hat errata applicability for managed Linux systems.
  • Check vulnerability scanner findings against vendor package status.
  • Document any systems awaiting vendor-specific updates or exceptions.
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-122: 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-2026-2447 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
3ADP providers
45Source 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-2026-2447Attack 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
CVECVE Program Container
redhat-SADPlibvpx: Heap buffer overflow in libvpx
other:Red Hat severity ratingcvssV3_1
  • 2026-02-16T15:01:25.122Z: Reported to Red Hat.
  • 2026-02-16T14:13:23.559Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox115.32.1, 140.7.1, 147.0.4Listed
MozillaThunderbird140.7.2, 147.0.2Listed
Weakness

CWE details

CWE-122

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

CWE-122 · source CWE mapping

Heap-based Buffer Overflow

Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs