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CVE Record

CVE-2026-2792: Memory safety bugs fixed in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148

Memory safety bugs present in Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

Mozilla fixed memory safety bugs in Firefox and Thunderbird that showed evidence of memory corruption. Mozilla states some could likely be exploited to run arbitrary code with enough effort. Because these are widely deployed desktop applications and the CVSS score is 9.8, unpatched endpoints should be treated as urgent exposure.

Executive priority

Treat this as a priority endpoint patching issue. The business risk is arbitrary code execution through common user applications, with confidentiality, integrity, and availability impact rated high. No active exploitation is cited, but the severity and product reach justify rapid remediation.

Technical view

CVE-2026-2792 covers memory safety issues, mapped to CWE-787, affecting Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird ESR 140.7. Fixes are listed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird ESR 140.8. The vector is CVSS 3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Likely exposure

Exposure is likely on endpoints or server images running the named Firefox or Thunderbird versions before the fixed releases. Linux distributions may also be exposed through vendor-packaged Mozilla builds, as indicated by Red Hat advisories and VEX references.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. Mozilla says the bugs showed memory corruption and presumes some could be exploited for arbitrary code execution with enough effort. That supports high urgency, but not a claim of observed exploitation.

Researcher notes

The bundle identifies grouped Mozilla memory safety bugs via Bugzilla IDs and multiple Mozilla advisories. Details appear limited, which is common for memory-corruption issues. Avoid assuming a specific exploit path beyond Mozilla's statement that some bugs could be exploitable for arbitrary code execution.

Mitigation direction

  • Upgrade Firefox to 148 or Firefox ESR to 140.8 or later.
  • Upgrade Thunderbird to 148 or Thunderbird ESR to 140.8 or later.
  • Apply Red Hat security advisories where Mozilla packages are distribution-managed.
  • Check Mozilla and OS vendor guidance for any environment-specific remediation.
  • Prioritize managed endpoints where browser or mail client patching is delayed.

Validation and detection

  • Inventory Firefox and Thunderbird versions across managed endpoints.
  • Confirm no systems remain on Firefox 147 or Firefox ESR 140.7.
  • Confirm no systems remain on Thunderbird 147 or Thunderbird ESR 140.7.
  • Verify Red Hat advisory applicability for installed distribution packages.
  • Review vulnerability scanner results against CVE-2026-2792 after 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-787: 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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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-2792 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
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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
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
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-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

9.8Critical
CVSS 3.1 vector shape for CVE-2026-2792Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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
other:ssvccvssV3_1
redhat-SADPfirefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148
other:Red Hat severity ratingcvssV3_1
  • 2026-02-24T14:04:09.479Z: Reported to Red Hat.
  • 2026-02-24T13:33:22.842Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox140.8, 148Listed
MozillaThunderbird140.8, 148Listed
Weakness

CWE details

CWE-787

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