Site isolation issue in the Networking component (Mozilla Firefox)

CVE-2026-16387
CRITICAL 9.8

At a glance

Source
NVD
EPSS
EPSS 0.28 % · percentile 21 ()
State
PUBLISHED
Published
Updated
Assigner
mozilla
NVD status
Analyzed

Description

Site isolation issue in the Networking component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

Weaknesses (CWE)

  • CWE-346 — Origin Validation Error
  • CWE-284 — Improper Access Control
  • CWE-200 — Exposure of Sensitive Information to an Unauthorized Actor

References

Scores

VersionScoreVectorScored by
CVSS 3.1CRITICAL 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCISA-ADP
CVSS 3.1CRITICAL 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Mozilla · Firefoxunaffected 140.13 ≤ 140.* ; unaffected 153 ≤ *
Mozilla · Thunderbirdunaffected 140.13 ≤ 140.* ; unaffected 153 ≤ *

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD