What is CVE-2025-8028?

CVE-2025-8028 is a critical-severity vulnerability in Mozilla Firefox, classified under CWE-1332. CVSS score: 9.8/10. Published 2025-07-22.

How severe is CVE-2025-8028?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2025-8028 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Mozilla Firefox

CVE-2025-8028

On arm64, a WASM `br_table` instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrect computation of the branch address. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

Published 2025-07-22 · last modified 2026-09-30.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (41.2th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000

Affected products

Mozilla Firefox — versions 115.26, 128.13, 140.1
Mozilla Thunderbird — versions 128.13, 140.1, 141

Weakness classification (CWE)

CWE-1332

Public proof-of-concept exploits

w4zu/Debian_

References

bugzilla.mozilla.org/show_bug.cgi (Permissions Required)
www.mozilla.org/security/advisories/mfsa2025-56/ (Vendor Advisory)
www.mozilla.org/security/advisories/mfsa2025-57/ (Vendor Advisory)
www.mozilla.org/security/advisories/mfsa2025-58/ (Vendor Advisory)
www.mozilla.org/security/advisories/mfsa2025-59/ (Vendor Advisory)
www.mozilla.org/security/advisories/mfsa2025-61/ (Vendor Advisory)
www.mozilla.org/security/advisories/mfsa2025-62/ (Vendor Advisory)
www.mozilla.org/security/advisories/mfsa2025-63/ (Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2025-8028?: CVE-2025-8028 is a critical-severity vulnerability in Mozilla Firefox, classified under CWE-1332. CVSS score: 9.8/10. Published 2025-07-22.
How severe is CVE-2025-8028?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-8028 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.