CVE-2025-1020

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.54% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 45.1% of scored records. A rank, not a probability.

NVD base score

9.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-10-05.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2025-02-04 13:58Z1 YR AGO

Last updated

2026-04-13 14:25Z6 MO AGO

Reserved

2025-02-04

Assigning CNA

mozilla

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

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

Weaknesses

• CWE-787Out-of-bounds WriteBase
• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')Base

Data version

5.2

Document digest

0e359016742d53b8305bd53abe7c2874e17acedca28485364c79c3d4abda177f

• bugzilla.mozilla.orgMemory safety bugs fixed in Firefox 135 and Thunderbird 135https://bugzilla.mozilla.org/buglist.cgi?bug_id=1939063%2C1942169
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2025-07/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2025-11/