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CVE Record

CVE-2026-7323: Memory safety bugs fixed in Thunderbird ESR 140.10.1 and Thunderbird 150.0.1

Memory safety bugs present in Thunderbird ESR 140.10.0 and Thunderbird 150.0.0. 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 150.0.1, Firefox ESR 140.10.1, Thunderbird 150.0.1, and Thunderbird 140.10.1.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-7323 covers Mozilla memory safety bugs that could corrupt memory. Mozilla says some issues could likely be exploited to run arbitrary code with enough effort. The source bundle names Thunderbird 140.10.0/150.0.0 as vulnerable and fixed releases for Thunderbird and Firefox.

Executive priority

Treat as a high-priority endpoint patching item. The issue is not shown as actively exploited, but the potential impact is arbitrary code execution in common user-facing software, so delay increases avoidable business risk.

Technical view

The issue is classified as CWE-119 and CWE-787, with CVSS 3.1 score 7.5. The vector requires network reachability and user interaction, no privileges, high attack complexity, and potential high confidentiality, integrity, and availability impact. Evidence supports possible arbitrary code execution, but not active exploitation.

Likely exposure

Exposure is most likely on endpoints running affected Mozilla Thunderbird or Firefox builds, including vendor-packaged deployments. Red Hat references indicate downstream advisory tracking exists, so Linux fleets should verify package status against their distribution channels, not only upstream Mozilla versions.

Exploitation context

The bundle does not show CISA KEV listing or cited evidence of active exploitation. Mozilla’s wording supports plausible exploitation after additional effort, due to memory corruption, but the evidence provided does not prove public weaponization or exploitation in the wild.

Researcher notes

The evidence is advisory-level and groups multiple memory safety bugs. Bugzilla IDs are referenced, but the bundle does not provide detailed root-cause material or exploit primitives. Avoid assuming a specific exploit path beyond Mozilla’s stated memory-corruption and possible arbitrary-code-execution assessment.

Mitigation direction

  • Update Thunderbird to Mozilla’s fixed 150.0.1 or 140.10.1 releases as applicable.
  • Update Firefox to Mozilla’s fixed 150.0.1 or ESR 140.10.1 releases as applicable.
  • Apply relevant Red Hat security advisories where Mozilla packages are distribution-managed.
  • Confirm endpoint management tools are enforcing the corrected browser and mail-client package versions.
  • Review Mozilla and vendor advisories for any later superseding fixes.

Validation and detection

  • Inventory Firefox and Thunderbird versions across managed endpoints.
  • Check package source and installed version against Mozilla and Red Hat advisory records.
  • Verify vulnerable Thunderbird 140.10.0 and 150.0.0 builds are no longer present.
  • Confirm distribution packages map to fixed vendor errata before closing remediation tickets.
  • Document any unsupported or manually installed Mozilla applications for separate remediation.
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-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.

Open ATT&CK lookup
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.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-7323 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
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:H/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
31Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical 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
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
7.3CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L3.93.4CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-7323Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:H/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: Memory safety bugs fixed in Firefox ESR 140.10.1 and Firefox 150.0.1
other:Red Hat severity ratingcvssV3_1
  • 2026-04-28T15:01:06.217Z: Reported to Red Hat.
  • 2026-04-28T13:49:10.299Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox140.10.1, 150.0.1Listed
MozillaThunderbird140.10.1, 150.0.1Listed
Weakness

CWE details

CWE-119CWE-787

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

CWE-119 · source CWE mapping

Improper Restriction of Operations within the Bounds of a Memory Buffer

Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-787 · source CWE mapping

Out-of-bounds Write

Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs