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CVE Record

CVE-2026-6752: Incorrect boundary conditions in the WebRTC component

Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-6752 is a high-severity Mozilla WebRTC boundary-condition flaw. Mozilla says it was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. A successful attack could have serious confidentiality, integrity, and availability impact, but the supplied sources do not show active exploitation.

Executive priority

Prioritize remediation in the high-severity endpoint patch cycle. Accelerate patching for users with routine web exposure, managed Linux desktops, or Thunderbird deployments. Current sources do not justify emergency incident response solely on exploitation grounds.

Technical view

The issue is described as incorrect boundary conditions in WebRTC, mapped to CWE-119 and CWE-131. CVSS 3.1 is 7.5 with network attack vector, high attack complexity, no privileges, required user interaction, unchanged scope, and high CIA impact. Public technical detail is limited in the provided bundle.

Likely exposure

Organizations using Mozilla Firefox, Firefox ESR, or Thunderbird below the fixed releases may be exposed. Red Hat also tracks related affected packages and errata. Exposure is most relevant on endpoints where users browse web content or use affected Thunderbird builds.

Exploitation context

The bundle marks KEV as false and provides no cited evidence of active exploitation. The CVSS vector indicates exploitation would require user interaction and high attack complexity, but no privileges. Do not assume exploitation in the wild from these sources alone.

Researcher notes

Public sources identify the vulnerable component and fixed releases but do not include enough detail for root-cause reconstruction. Focus validation on version and package state. Avoid extrapolating affected version ranges beyond Mozilla and vendor advisory statements.

Mitigation direction

  • Upgrade Firefox to 150 or a later vendor-supported fixed release.
  • Upgrade Firefox ESR to 115.35, 140.10, or later supported fixed releases.
  • Upgrade Thunderbird to 150, 140.10, or later fixed releases.
  • For Red Hat systems, apply the relevant RHSA updates for Mozilla packages.
  • Check Mozilla and OS vendor advisories for deployment-specific guidance.

Validation and detection

  • Inventory Firefox, Firefox ESR, and Thunderbird versions across managed endpoints.
  • Confirm installed versions meet or exceed the fixed Mozilla releases.
  • Check Red Hat package advisory applicability on Linux systems.
  • Verify patch deployment through endpoint management or package inventory.
  • Monitor vendor advisories for revised affected-version or mitigation details.
Prepared
Confidence
medium
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-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-131: 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
cve · low confidence lookup

CVE-2026-6752 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
37Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

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-2026-6752Attack 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: Incorrect boundary conditions in the WebRTC component
other:Red Hat severity ratingcvssV3_1
  • 2026-04-21T14:01:16.112Z: Reported to Red Hat.
  • 2026-04-21T12:40:49.079Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox115.35, 140.10, 150Listed
MozillaThunderbird140.10, 150Listed
Weakness

CWE details

CWE-119CWE-131

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-131 · source CWE mapping

Incorrect Calculation of Buffer Size

Incorrect Calculation of Buffer Size represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs