Cyber Resilience

CVE-2025-8027

Medium

Published: 22 July 2025

Published
22 July 2025
Modified
13 April 2026
KEV Added
—
Patch
—
CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS Score 0.0049 65.9th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-8027 is a medium-severity Use of Uninitialized Variable (CWE-457) vulnerability in Mozilla Firefox. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 34.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1,…

more

Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

CWE(s)
CWE-457

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

mozilla
firefox
≤ 115.26.0 · ≤ 141.0 · 128.0 — 128.13.0
mozilla
thunderbird
≤ 128.13.0 · ≤ 141.0 · 140.0 — 140.1.0

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References