Review reviewCritical

CVE-2026-2799

Mozilla Firefox, Thunderbird, Red Hat Enterprise Linux 10

Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.

CVSS
9.8
EPSS
0.32%
24.6% percentile
CISA KEV
Not listed
Published
2026.02.24
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.32%
Technical severityCVSS 9.8

Vulnerability overview

Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.

Affected product and versions

Product
Mozilla Firefox, Thunderbird, Red Hat Enterprise Linux 10
Affected versions
< 148.0
Fixed versions
148.0

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Mozilla Firefox, Thunderbird, Red Hat Enterprise Linux 10 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-416
CVE-2026-2799 — Mozilla Firefox, Thunderbird, Red Hat Enterprise Linux 10 | SECUFOCUS NOW