Review reviewHigh

CVE-2026-8390

Mozilla Firefox, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150.0.3.

CVSS
7.3
EPSS
0.26%
17.4% percentile
CISA KEV
Not listed
Published
2026.05.12
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.26%
Technical severityCVSS 7.3

Vulnerability overview

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150.0.3.

Affected product and versions

Product
Mozilla Firefox, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6
Affected versions
< 150.0.3
Fixed versions
150.0.3

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Mozilla Firefox, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 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:L/I:L/A:L
CWE
CWE-416, CWE-825