Security readout for executives and security teams
Plain-English summary
CVE-2026-4704 is a high-severity denial-of-service flaw in Mozilla’s WebRTC signaling component. A remote, unauthenticated actor could cause availability impact. Mozilla says it is fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9. There is no provided evidence of active exploitation.
Executive priority
Treat as a timely patching item, not an emergency breach indicator. The business risk is service disruption on user endpoints, not confirmed data theft. Prioritize rapid update deployment through normal endpoint management channels.
Technical view
The issue is categorized as CWE-400, uncontrolled resource consumption, with CVSS 3.1 score 7.5: network attack vector, low complexity, no privileges, no user interaction, and high availability impact. The source bundle identifies the vulnerable component as WebRTC: Signaling and affected Mozilla Firefox and Thunderbird release lines.
Likely exposure
Exposure is most relevant where Firefox or Thunderbird versions older than the fixed releases are installed and WebRTC functionality is reachable. Browser and email-client deployments across workstations, VDI, and managed endpoints should be inventoried.
Exploitation context
The CVSS vector indicates remote, unauthenticated, no-user-interaction denial-of-service potential. The CVE is not listed as CISA KEV in the provided data, and the sources supplied do not state active exploitation or public weaponization.
Researcher notes
Public details are limited in the provided bundle. Bugzilla and Mozilla advisories are the primary references. Avoid assuming code execution or confidentiality impact; the supplied CVSS and description support denial-of-service only.
Mitigation direction
- Update Firefox to version 149 or later where applicable.
- Update Firefox ESR to version 140.9 or later where applicable.
- Update Thunderbird to version 149 or later where applicable.
- Update Thunderbird 140.x deployments to 140.9 or later.
- Check Mozilla advisories for platform-specific guidance and release availability.
Validation and detection
- Inventory deployed Firefox, Firefox ESR, and Thunderbird versions.
- Confirm endpoints report the fixed versions or later.
- Review software management logs for successful Mozilla update deployment.
- Monitor Mozilla advisories and Bugzilla for additional clarification.
- Prioritize internet-facing, shared, or high-availability user environments.
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-400: 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-2026-4704 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
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.
CVSS vector scores
1 official scoreWe 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:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.mozilla.org/show_bug.cgi?id=2014868CVE reference
- https://www.mozilla.org/security/advisories/mfsa2026-20/CVE reference
- https://www.mozilla.org/security/advisories/mfsa2026-22/CVE reference
- https://www.mozilla.org/security/advisories/mfsa2026-23/CVE reference
- https://www.mozilla.org/security/advisories/mfsa2026-24/CVE reference
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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.