Security readout for executives and security teams
Plain-English summary
CVE-2026-2796 is a critical Mozilla issue in JavaScript: WebAssembly JIT compilation. In business terms, it affects browser and mail-client code that processes web content, and Mozilla says it was fixed in Firefox 148 and Thunderbird 148.
Executive priority
Treat as urgent patching for managed browsers and Thunderbird clients because the issue is critical, remotely reachable by CVSS, and affects common user-facing software. Do not claim active exploitation from the supplied evidence.
Technical view
The source describes a JIT miscompilation in the JavaScript: WebAssembly component, mapped to CWE-843. CVSS 3.1 is 9.8 with network attack vector, low complexity, no privileges, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where Mozilla Firefox or Thunderbird has not been updated to the fixed 148 release line identified in the bundle. The provided evidence does not name other affected products or platforms.
Exploitation context
The supplied bundle marks KEV as false and provides no cited evidence of active exploitation. The high CVSS score indicates serious potential impact, but exploitation status should not be treated as confirmed from these sources.
Researcher notes
Public details are limited in the bundle. The useful confirmed facts are component, weakness class, CVSS vector, Mozilla fixed releases, and Red Hat tracking. Avoid assuming exploitability mechanics beyond JIT miscompilation in JavaScript: WebAssembly.
Mitigation direction
- Update Firefox to the fixed 148 release or later per Mozilla guidance.
- Update Thunderbird to the fixed 148 release or later per Mozilla guidance.
- Check Mozilla advisories MFSA 2026-13 and MFSA 2026-16 for product-specific details.
- Monitor vendor and distribution advisories for downstream package availability.
Validation and detection
- Inventory Firefox and Thunderbird installations across managed endpoints and servers.
- Confirm installed versions include the Firefox 148 or Thunderbird 148 fixes.
- Review vulnerability scanners for CVE-2026-2796 findings and false-positive notes.
- Check Red Hat advisories if Mozilla packages are supplied through Red Hat channels.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-843: 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 lookupCVE-2026-2796 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- 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
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.
SSVC decision data
CVSS vector scores
2 official scoresWe 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H1.65.9redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-02-24T14:03:05.463Z: Reported to Red Hat.
- 2026-02-24T13:33:26.775Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.mozilla.org/show_bug.cgi?id=2013165CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2026-13/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2026-16/CVE reference, mozilla
- https://access.redhat.com/security/cve/CVE-2026-2796CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2442301CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2796.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Access of Resource Using Incompatible Type ('Type Confusion')
Access of Resource Using Incompatible Type ('Type Confusion') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.