LiveActive security incident?Get immediate response
CVE Record

CVE-2026-8091: Incorrect boundary conditions in the Audio/Video: Playback component

Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.

CriticalCVSS 9.8Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

A boundary-handling flaw in Mozilla’s audio/video playback component could cause serious security failures when affected software processes content. Its 9.8 CVSS rating reflects potential loss of data confidentiality, integrity, and availability. The supplied evidence confirms fixes but does not establish real-world exploitation.

Executive priority

Treat remediation as urgent because the stated impact spans data theft, unauthorized modification, and service disruption without privileges or user interaction. Prioritize broadly deployed and externally exposed endpoints, while avoiding claims of active attacks until credible evidence emerges.

Technical view

CVE-2026-8091 involves incorrect boundary conditions in audio/video playback, categorized as CWE-754 and CWE-805. The CVSS assessment describes a network-reachable, low-complexity issue requiring neither privileges nor user interaction, with high confidentiality, integrity, and availability impact. Public details supplied here do not identify the precise memory failure or demonstrated outcome.

Likely exposure

Potential exposure includes installations not yet updated to the applicable fixed release: Firefox 150, Firefox ESR 140.10.1 or 115.35.2, Thunderbird 150, and Thunderbird 140.10.1. The bundle does not provide complete affected-version ranges, so inventory findings should be checked against the relevant Mozilla or Red Hat advisory.

Exploitation context

The supplied bundle does not report active exploitation, and the CVE is not identified there as a CISA KEV entry. The high CVSS score indicates serious theoretical exploitability and impact, but no public proof, attack chain, or confirmed exploitation outcome is provided.

Researcher notes

The public description is unusually terse. It identifies boundary-condition and length-value handling weaknesses but does not disclose the triggering input, affected code path, corruption primitive, sandbox implications, or proven execution capability. Researchers should distinguish the CVSS worst-case assessment from demonstrated technical impact.

Mitigation direction

  • Update Firefox to version 150 or the applicable fixed ESR release.
  • Update Thunderbird to version 150 or ESR 140.10.1, as applicable.
  • Apply the relevant Red Hat security errata to vendor-managed Mozilla packages.
  • If updating is delayed, consult Mozilla or Red Hat guidance for supported temporary controls.

Validation and detection

  • Inventory Firefox and Thunderbird versions across endpoints and managed server images.
  • Confirm each installation meets its branch-specific fixed version after updating and restarting.
  • Check Red Hat package versions against the applicable published security erratum.
  • Review update-management reports for failed, deferred, or unmanaged Mozilla installations.
Prepared
Confidence
medium
Sources
10

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-754: 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-805: 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-2026-8091 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
32Source 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-2026-8091Attack 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 Audio/Video: Playback component
other:Red Hat severity ratingcvssV3_1
  • 2026-05-07T13:00:55.414Z: Reported to Red Hat.
  • 2026-05-07T12:45:05.530Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox115.35.2, 140.10.1, 150Listed
MozillaThunderbird140.10.1, 150Listed
Weakness

CWE details

CWE-754CWE-805

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