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CVE Record

CVE-2026-5732: Incorrect boundary conditions, integer overflow in the Graphics: Text component

Incorrect boundary conditions, integer overflow in the Graphics: Text component. This vulnerability was fixed in Firefox 149.0.2, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.

HighCVSS 8.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-5732 is a high-severity Mozilla flaw in text rendering. A user could be at risk when opening or viewing crafted web or email content in vulnerable Firefox or Thunderbird versions. Mozilla states the issue is fixed in current listed releases.

Executive priority

Treat as a near-term endpoint patching priority. It affects common user-facing applications and has high impact scoring, but the provided evidence does not show known active exploitation.

Technical view

The issue is described as incorrect boundary conditions causing integer overflow in Mozilla Graphics: Text. CVSS 3.1 is 8.8 with network attack vector, low complexity, no privileges, required user interaction, and high confidentiality, integrity, and availability impact.

Likely exposure

Exposure is most likely on endpoints running Firefox, Firefox ESR, Thunderbird, or Thunderbird ESR below Mozilla's fixed releases. The bundle does not provide exact vulnerable version ranges beyond naming the fixed versions.

Exploitation context

The bundle marks KEV as false and provides no cited evidence of active exploitation. The CVSS vector still indicates practical remote attack conditions requiring user interaction, so phishing or malicious-content delivery is plausible but unconfirmed.

Researcher notes

Key uncertainty is the exact vulnerable version range and exploitability details; the Bugzilla entry may contain restricted information. Avoid assuming exploitation in the wild. Prioritize version verification, vendor advisory mapping, and distro package status.

Mitigation direction

  • Update Firefox to 149.0.2 or later where applicable.
  • Update Firefox ESR to 140.9.1 or later where applicable.
  • Update Thunderbird to 149.0.2 or later where applicable.
  • Update Thunderbird ESR to 140.9.1 or later where applicable.
  • For Red Hat-managed systems, apply relevant RHSA advisories.
  • Monitor Mozilla and distribution vendor guidance for clarifications.

Validation and detection

  • Inventory installed Firefox and Thunderbird versions across managed endpoints.
  • Confirm Firefox is at least 149.0.2 or ESR 140.9.1 where applicable.
  • Confirm Thunderbird is at least 149.0.2 or ESR 140.9.1 where applicable.
  • Check Linux package status against applicable Red Hat errata.
  • Review vulnerability scanner findings for CVE-2026-5732 after patching.
Prepared
Confidence
high
Sources
11

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-190: 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-2026-5732 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
33Source 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
8.8CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

8.8High
CVSS 3.1 vector shape for CVE-2026-5732Attack 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: Incorrect boundary conditions, integer overflow in the Graphics: Text component
other:Red Hat severity ratingcvssV3_1
  • 2026-04-07T13:01:39.095Z: Reported to Red Hat.
  • 2026-04-07T12:43:12.829Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox140.9.1, 149.0.2Listed
MozillaThunderbird140.9.1, 149.0.2Listed
Weakness

CWE details

CWE-190

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

CWE-190 · source CWE mapping

Integer Overflow or Wraparound

Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs