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CVE Record

CVE-2026-2773: Incorrect boundary conditions in the Web Audio component

Incorrect boundary conditions in the Web Audio 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-2026-2773 is a critical Mozilla Web Audio memory boundary issue. The sources say it is fixed in current Firefox, Firefox ESR, and Thunderbird releases. Businesses should treat outdated browsers and mail clients as high-priority endpoint risk because they routinely process untrusted web and message content.

Executive priority

Treat this as urgent patching for browser and mail-client fleets. There is no source-backed evidence of active exploitation here, but the critical score and memory-safety class justify rapid remediation across managed endpoints.

Technical view

The issue is described as incorrect boundary conditions in Mozilla’s Web Audio component and maps to CWE-119. CVSS 3.1 is 9.8 with network attack vector, low complexity, no privileges, and high confidentiality, integrity, and availability impact. Mozilla lists fixed releases; Red Hat published related advisories.

Likely exposure

Exposure is most likely on endpoints, servers, or packaged Linux systems running Mozilla Firefox, Firefox ESR, or Thunderbird before the fixed vendor releases. Red Hat advisory references indicate downstream package exposure should be checked through Red Hat errata and CSAF data.

Exploitation context

The bundle does not show CISA KEV listing or cited active exploitation. The CVSS vector indicates serious remote exploit potential, but the provided sources do not establish exploitation in the wild or provide public exploit details.

Researcher notes

Evidence is limited to advisory-level detail. The Bugzilla reference is included, but the bundle does not provide exploit mechanics. Avoid assuming affected version ranges beyond vendor-fixed releases and downstream Red Hat mappings.

Mitigation direction

  • Update Firefox to 148 or the fixed supported ESR release listed by Mozilla.
  • Update Thunderbird to 148 or 140.8 where applicable.
  • Apply relevant Red Hat security advisories for packaged Mozilla components.
  • Check Mozilla and OS vendor guidance for branch-specific upgrade paths.
  • Prioritize managed endpoints that process untrusted web or email content.

Validation and detection

  • Inventory installed Firefox, Firefox ESR, and Thunderbird versions across managed assets.
  • Confirm versions match or exceed the fixed releases named by Mozilla.
  • Verify relevant Red Hat RHSA updates are installed on affected systems.
  • Review vulnerability scanner results against vendor advisory identifiers.
  • Monitor Mozilla and Red Hat pages for revised impact or remediation guidance.
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.

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cve · low confidence lookup

CVE-2026-2773 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
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
7.5CVSS 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-2026-2773Attack 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 Web Audio component
other:Red Hat severity ratingcvssV3_1
  • 2026-02-24T14:04:12.678Z: Reported to Red Hat.
  • 2026-02-24T13:33:10.177Z: 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-119

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