CVE-2026-4729

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.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total 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

0.34% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 27.6% 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 2026-07-15.

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

2026-03-24 12:30Z7 MO AGO

Last updated

2026-07-15 00:49Z3 MO AGO

Reserved

2026-03-23

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-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')Base
• CWE-825Expired Pointer DereferenceBase

Data version

5.2

Document digest

e9d4dee5c239556749435bf57289fdc5d713cf042e1e726486053f116c932b87

• bugzilla.mozilla.orgMemory safety bugs fixed in Firefox 149 and Thunderbird 149https://bugzilla.mozilla.org/buglist.cgi?bug_id=1944033%2C1997282%2C2009213%2C2011412%2C2021925%2C2022034
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-20/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-23/
• access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-4729vdb-entryx_refsource_REDHAT
• bugzilla.redhat.comRHBZ#2450745https://bugzilla.redhat.com/show_bug.cgi?id=2450745issue-trackingx_refsource_REDHAT
• security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4729.jsonx_sadp-csaf-vex