Site isolation issue in the WebExtensions component (Mozilla Firefox)

CVE-2026-74960
HIGH 8.1

At a glance

Source
NVD
EPSS
EPSS 0.22 % · percentile 13 ()
State
PUBLISHED
Published
Updated
Assigner
mozilla
NVD status
Analyzed

Description

Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

Weaknesses (CWE)

  • CWE-346 — Origin Validation Error
  • CWE-284 — Improper Access Control

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 8.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:NCISA-ADP
CVSS 3.1HIGH 8.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:NNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Mozilla · Firefoxunaffected 140.14 ≤ 140.* ; unaffected 153.1 ≤ 153.* ; unaffected 154 ≤ *
Mozilla · Thunderbirdunaffected 140.14 ≤ 140.* ; unaffected 153.1 ≤ 153.* ; unaffected 154 ≤ *

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