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CVE Record

CVE-2026-2757: Incorrect boundary conditions in the WebRTC: Audio/Video component

Incorrect boundary conditions in the WebRTC: Audio/Video component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, 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

CVE-2026-2757 is a critical Mozilla WebRTC audio/video boundary-condition flaw fixed in Firefox, Firefox ESR, and Thunderbird releases. The CVSS 9.8 rating means a network attacker may not need authentication or user interaction, but the supplied sources do not confirm active exploitation.

Executive priority

Treat as urgent enterprise browser and mail-client patching. No active exploitation is cited, but the critical CVSS score and no-user-interaction vector justify accelerated remediation across managed endpoints.

Technical view

Mozilla describes incorrect boundary conditions in the WebRTC Audio/Video component. The record lists CVSS 3.1 AV:N/AC:L/PR:N/UI:N with high confidentiality, integrity, and availability impact. Fixed versions are Firefox 148, Firefox ESR 115.33 and 140.8, Thunderbird 148 and 140.8.

Likely exposure

Exposure is most likely on endpoints, VDI images, servers, or packaged Linux builds running Firefox, Firefox ESR, Thunderbird, or affected Red Hat-distributed Mozilla packages before the fixed releases.

Exploitation context

The bundle shows KEV=false and provides no cited evidence of active exploitation. The CVSS vector indicates potentially remote, low-complexity exploitation without authentication or user interaction, so patch urgency remains high despite incomplete exploitation evidence.

Researcher notes

Public detail is limited to Mozilla’s boundary-condition description, CVSS vector, fixed releases, Bugzilla reference, and Red Hat advisories. Avoid assuming exploitability mechanics, affected subversions, or indicators beyond the cited sources.

Mitigation direction

  • Update Firefox to 148 or applicable fixed ESR release.
  • Update Thunderbird to 148 or 140.8 where applicable.
  • Apply relevant Red Hat security errata for managed Linux packages.
  • Check Mozilla and Red Hat advisories for platform-specific guidance.
  • Prioritize internet-facing, high-risk, and unmanaged endpoint populations.

Validation and detection

  • Inventory installed Firefox, Firefox ESR, and Thunderbird versions.
  • Confirm versions meet or exceed the fixed releases named by Mozilla.
  • Verify Red Hat advisory remediation status for affected package streams.
  • Review endpoint management data for update failures or stale images.
  • Record exceptions where vendor guidance is unavailable or incomplete.
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

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cwe · low confidence lookup

CWE-1384: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-2757 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
35Source 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
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
7.1CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L1.65.5redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2026-2757Attack 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
cvssV3_1other:ssvc
redhat-SADPfirefox: thunderbird: Incorrect boundary conditions in the WebRTC: Audio/Video component
other:Red Hat severity ratingcvssV3_1
  • 2026-02-24T14:04:32.278Z: Reported to Red Hat.
  • 2026-02-24T13:32:57.740Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox115.33, 140.8, 148Listed
MozillaThunderbird140.8, 148Listed
Weakness

CWE details

CWE-1384

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

CWE-1384 · source CWE mapping

Improper Handling of Physical or Environmental Conditions

Improper Handling of Physical or Environmental Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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