CVE-2025-8027

Name: CVE-2025-8027
Creator: NVD / NIST
Published: 2025-07-22T21:15:49.83+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.35%

Last modified Jun 17, 2026

CVE-2025-8027 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 0.35% chance of exploitation in the next 30 days.

Description

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, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS Probability

0.35%

27.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-457

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 115.26.0
Mozilla	Firefox	< 141.0
Mozilla	Firefox	>= 128.0, < 128.13.0
Mozilla	Firefox	>= 140.0, < 140.1.0
Mozilla	Thunderbird	< 128.13.0
Mozilla	Thunderbird	< 141.0
Mozilla	Thunderbird	>= 140.0, < 140.1.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1968423Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-56/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-57/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-58/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-59/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-61/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-62/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-63/Vendor Advisory
https://lists.debian.org/debian-lts-announce/2025/07/msg00016.html

Timeline

Published: Jul 22, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-8027?

How severe is CVE-2025-8027?

CVE-2025-8027 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.35% probability of exploitation in the next 30 days.

How do I fix CVE-2025-8027?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-8027?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST